Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
TRAINING MANUAL
Embraer ERJ-190 Series (GE CF34)
B1.1 and B2 (-sub) categories
AIR CONDITIONING
(ATA 21)
Level 3
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 1
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
THIS PAGE IS INTENTIONALLY LEFT BLANK
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
TABLE OF CONTENTS
ATA 21-00 AIR CONDITIONING GENERAL .................................................. 6
INTRODUCTION ........................................................................................ 6
ELECTRONIC COMPARTMENTS VENTILATION ................................... 10
CONTROLS ............................................................................................. 14
INDICATIONS .......................................................................................... 16
ATA 21-20 AIR CONDITIONING DISTRIBUTION ........................................ 18
INTRODUCTION ...................................................................................... 18
DESCRIPTION ......................................................................................... 20
ATA 21-29 LOW PRESSURE GROUND SUPPLY ....................................... 30
COMPONENTS ........................................................................................ 32
OPERATION ............................................................................................ 40
DIAGNOSTIC AND TESTS ...................................................................... 46
ATA 21-26 AVIONICS COMPARTMENT ..................................................... 48
INTRODUCTION, DESCRIPTION ............................................................ 48
COMPONENTS ........................................................................................ 50
OPERATION ............................................................................................ 54
DIAGNOSTIC AND TEST......................................................................... 58
FORWARD CARGO COMPARTMENT VENTILATION ................................ 60
INTRODUCTION, DESCRIPTION ............................................................ 60
COMPONENTS ........................................................................................ 62
OPERATION ............................................................................................ 64
DIAGNOSTIC AND TEST......................................................................... 66
ELECTRONIC RACK VENTILATION SYSTEM ........................................... 68
INTRODUCTION ...................................................................................... 68
DESCRIPTION ......................................................................................... 70
COMPONENTS ........................................................................................ 72
OPERATION ............................................................................................ 74
DIAGNOSTIC AND TEST......................................................................... 80
ATA 21-30 PRESSURIZATION .................................................................... 82
INTRODUCTION ...................................................................................... 82
DESCRIPTION ......................................................................................... 84
COMPONENTS ........................................................................................ 86
OPERATION ............................................................................................ 98
DIAGNOSTIC AND TEST....................................................................... 114
ATA 21-50 COOLING ................................................................................ 116
INTRODUCTION .................................................................................... 116
DESCRIPTION ....................................................................................... 118
ISSUE 1, 24 Sep 2014
COMPONENTS ...................................................................................... 122
OPERATION .......................................................................................... 136
TRAINING INFORMATION POINTS....................................................... 140
DIAGNOSTIC AND TEST ....................................................................... 142
ATA 21-60 TEMPERATURE CONTROL .................................................... 144
INTRODUCTION .................................................................................... 144
DESCRIPTION ....................................................................................... 146
COMPONENTS ...................................................................................... 152
OPERATION .......................................................................................... 154
DIAGNOSTIC AND TEST ....................................................................... 156
ATA 21-00 MEL.......................................................................................... 158
FOR TRAINING PURPOSES ONLY
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
TABLE OF FIGURES
THE AIR CONDITIONING SYSTEM .............................................................. 7
AIR CONDITIONING BLOCK DIAGRAM ...................................................... 9
PASSENGER-CABIN ZONE TEMPERATURE CONTROL BLOCK
DIAGRAM .................................................................................................... 11
PASSENGER-CABIN ZONE TEMPERATURE CONTROL BLOCK
DIAGRAM .................................................................................................... 13
INDICATION PANELS ................................................................................. 15
INDICATION ................................................................................................ 17
AIR CONDITIONING SCHEMATIC ............................................................. 19
AIR SUPPLY TO THE FLIGHT DECK ......................................................... 21
CABIN AIR DISTRIBUTION SYSTEM ......................................................... 23
GASPER VENTILATION SYSTEM .............................................................. 25
CABIN AIR RE CIRCULATION DIAGRAM ................................................. 27
RAM AIR VENTILATION SYSTEM ............................................................. 29
LOW PRESSURE SUPPLY ......................................................................... 31
THE DISTRIBUTION DUCT SYSTEM ......................................................... 33
MIXER ......................................................................................................... 35
SMOKE DETECTOR ................................................................................... 37
EMERGENCY RAM AIR VALVE ................................................................. 39
RECIRCULATION FANS ............................................................................. 41
RAM AIR VALVE OPERATION ................................................................... 43
SMOKE REMOVAL ..................................................................................... 45
CMC TESTS ................................................................................................ 47
FORWARD ELECTRONIC BAY .................................................................. 49
FAN FAILURES ........................................................................................... 51
FAN FAILURES ........................................................................................... 53
FORWARD ELECTRONIC FAN OPERATION ............................................ 55
MIDDLE ELECTRONIC BAY ....................................................................... 57
DIAGNOSTIC AND TEST ............................................................................ 59
FORWARD CARGO COMPARTMENT ....................................................... 61
FWD CARGO COMPARTMENT.................................................................. 63
OPERATING LOGIC ................................................................................... 65
DIAGNOSTIC AND TEST ............................................................................ 67
ELECTRONIC RACK VENTILATION LAYOUT .......................................... 69
COMPONENTS VIEW ................................................................................. 71
COMPONENTS VIEW ................................................................................. 73
OPERATION................................................................................................ 75
ISSUE 1, 24 Sep 2014
OPERATION ................................................................................................77
MAINTENANCE TEST PANEL OPERATION ..............................................79
MAINTENANCE TEST PANEL ....................................................................81
CABIN PRESSURE CONTROL SYSTEM ...................................................83
CABIN PRESSURE CONTROL SYSTEM COMPONENTS .........................85
PRESSURIZATION CONTROL PANEL ......................................................87
CABIN PRESSURIZATION CONTROLLER ................................................89
CPCS CONTROLLER .................................................................................91
OUTFLOW VALVE ......................................................................................93
POSITIVE PRESSURE RELIEF VALVE ......................................................95
NEGATIVE PRESSURE RELIEF .................................................................97
GROUND AND TAKEOFF MODES .............................................................99
CLIMB AND CRUISE MODES ................................................................... 101
DESCENT AND ABORT MODES .............................................................. 103
MANUAL MODE ........................................................................................ 105
ABNORMAL OPERATION ........................................................................ 107
EICAS INDICATIONS ................................................................................ 109
EICAS INDICATIONS (CONTINUED) ........................................................ 111
EICAS INDICATIONS (CONTINUED) ........................................................ 113
BUILT-IN TEST.......................................................................................... 115
AIR CONDITIONING SYSTEM .................................................................. 117
ECS PACK ................................................................................................ 119
FLOW CONTROL ...................................................................................... 121
FLOW CONTROL VALVE ......................................................................... 123
DUAL HEAT EXCHANGER ....................................................................... 125
AIR CYCLE MACHINE COMPONENTS .................................................... 127
CONDENSER ............................................................................................ 129
BYPASS VALVE ....................................................................................... 131
LOW LIMIT BYPASS VALVE, ADD HEAT VALVE AND ECS PACK
BYPASS VALVE ....................................................................................... 133
TEMPERATURE SENSORS...................................................................... 135
AIR CYCLE MACHINE OPERATION ........................................................ 137
ECS OFF LOGIC ....................................................................................... 139
PACK RELATED MESSAGES .................................................................. 141
PACK TESTS ............................................................................................ 143
AMS TEMPERATURE CONTROLLER...................................................... 145
COCKPIT ZONE CONTROL...................................................................... 147
FOR TRAINING PURPOSES ONLY
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
SINGLE CABIN ZONE CONFIGURATION ................................................ 149
TWO CABIN ZONE CONFIGURATION..................................................... 151
TRIM MODULATING VALVES .................................................................. 153
AUTOMATIC TEMPERATURE CONTROL ............................................... 155
CMC DIAGNOSTIC ................................................................................... 157
MEL - EXAMPLE ....................................................................................... 159
MEL - EXAMPLE ....................................................................................... 160
MEL - EXAMPLE ....................................................................................... 161
MEL - EXAMPLE ....................................................................................... 162
MEL - EXAMPLE ....................................................................................... 163
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FOR TRAINING PURPOSES ONLY
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
ATA 21-00 AIR CONDITIONING GENERAL
INTRODUCTION
The Environmental Control System (ECS) provides air conditioning for the
flight deck and passenger cabin, filtered cabin air re circulation, conditioned
air supply for gaspers, fan air cooling for avionics and emergency ram air
ventilation for flight deck smoke clearance.
The ECS provides cargo bay ventilation. The cargo bay ventilation system is
optional.
 Two identical ECS packs which condition fresh bleed air for cabin and
flight deck heating and cooling
 Optional trim air system to provide two cabin zone temperature
control
 Flow control valves to provide accurate modulation of pack air flow,
and all associated valves and sensors used for system built in test
 Avionic fan control and cargo compartment ventilation
 Cockpit smoke removal
 Provides environmental control system flow rate data used by the
cabin pressure control system to anticipate changes in cabin
pressure.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
THE AIR CONDITIONING SYSTEM
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
AIR CONDITIONING PACKS
Two ECS packs are installed in the wing-to-fuselage fairing. The AMS
controller controls the bleed airflow to each pack independently, through the
respective pack flow control valve (FCV). Engine # 1 supplies bleed air to the
pack # 1 while engine # 2 supplies bleed air to pack # 2. A single pack is
capable of keeping adequate cabin/cargo hold pressurization and
temperature. Single engine bleed can supply both ECS packs using the cross
bleed.
RE CIRCULATION FANS
Re circulated air from the passenger cabin and cockpit is ducted to the
mixing manifold via two re circulation fans located in the pressurized section
of the airplane.
The re circulation fans draw air from the re circulation bays and impel the air
back into the flight deck and cabin distribution system.The total flow entering
the cockpit and the passenger cabin is made up of approximately 52% fresh
air and 48% of re circulating air.
The re circulation fans are commanded off when DUMP button is pressed or
smoke is detected in the re circulation bay.
GASPER VENTILATION
The gasper air distribution system provides air to each pilot and passenger
positions.Air flowing from the mixing manifold through the gasper ducts
supplies the gasper ventilation system.
TRIM AIR (OPTIONAL)
The trim air system controls the amount of hot bleed air from the pack 2 into
the mixer for independent control of forward and aft cabin zones
temperatures. The trim air system is used for temperature control
improvement.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
AIR CONDITIONING BLOCK DIAGRAM
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
ELECTRONIC COMPARTMENTS VENTILATION
FORWARD ELECTRONIC BAY (E-BAY)
EMERGENCY RAM AIR VENTILATION
The forward e-bay comprises three fans, which provide forced cooling air for
# 1 Secondary Power Distribution Assembly (SPDA 1), Emergency
Integrated Control Centre (EICC) and all other avionics located in this e- bay.
The fans draw air from the cockpit and expel air toward the underfloor re
circulation bay. A flow sensor is used for fan/flow health monitoring to ensure
forward e-bay flow requirements.
The pack 1 ram air ventilation consists of a ventilation valve installed in
emergency ram ducting that connects the ram air duct to the pack 2 outlet
ducting. The emergency ram air valve is commanded open any time the
airplane is in flight and both air conditioning packs are commanded OFF or
failed OFF and the airplane’s flight altitude is less than 25000 ft.
CENTRE ELECTRONIC BAY (E-BAY)
The centre e-bay comprises three fans, which provide forced cooling air for
the centre e-bay electronics, Left Integrated Control Centre (LICC), Right
Integrated Control Centre (RICC) and SPDA 2. The fans draw air from the
rear cabin return and expel it toward the underfloor re circulation bay. Flow
sensors are used for fan/flow health monitoring.
The pack 2 ram air ventilation consists of a check valve installed in the
emergency ram air ducting that connects the ram air duct to the pack 2 outlet
ducting. The emergency ram air check valve does not require electronic
control. The emergency ram air check valve will be open whenever the
pressure in the ram air circuit is greater than cabin pressure.
FORWARD CARGO BAY VENTILATION (OPTIONAL)
The ECS provides ventilation for live animals in the forward cargo bay. This
optional system contains a fan on the side of the bay to provide underfloor re
circulation air into the bay. The system also contains a shutt off valve at the
outlet of the bay that closes in the event of fire and thus preventing halon
from leaving the bay. In addition, in the event of fire, forward cargo
compartment fans are commanded OFF to prevent halon from entering the
cabin.
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FOR TRAINING PURPOSES ONLY
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
PASSENGER-CABIN ZONE TEMPERATURE CONTROL BLOCK DIAGRAM
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 11
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
DISTRIBUTION
The distribution system receives airflow from the re circulation fans, cooling
packs, ram air system and ground equipment and distributes this air to the
cockpit, passenger cabin, gaspers, avionics compartments and forward cargo
compartment.
PRESSURIZATION CONTROL
The aircraft operates at altitudes where the oxygen density is not sufficient to
sustain life. The pressurization control keeps the aircraft cabin interior at a
safe pressure altitude. This protects the passengers and crew from the
effects of hypoxia (oxygen starvation).
COOLING
The cooling system receives hot bleed air from the APU (Auxiliary Power
Unit) or engines and supplies conditioned air to the distribution system.
TEMPERATURE CONTROL
The temperature control system provides independent closed loop
temperature control for the cockpit and one or two separate passenger cabin
zones.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
PASSENGER-CABIN ZONE TEMPERATURE CONTROL BLOCK DIAGRAM
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 13
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
CONTROLS
The air conditioning controls and indications are:
PRESSURIZATION CONTROL PANEL
Controls the pressurization of the aircraft, in AUTO and MANUAL mode. The
mode selector switch facilitates auto, manual mode selection or landing field
elevation settings. Manual selector enables direct control of the outflow valve.
Dump switch controls auto depressurization of the aircraft.
AIR CONDITIONING PANEL
PACK 1 switch controls the left Cooling Pack (AUTO-OFF) CKPT knob Controls the cockpit between 19 and 30 ∞C. RECIRC switch - Controls the re
circulation system (AUTO - OFF) PAX CABIN knob - Controls the passenger
cabin temperature between 19 and 30 ∞C. PACK 2 switch - Controls the right
Cooling Pack (AUTO - OFF)
FLIGHT ATTENDANT PANEL
Zone temperature control selector enables attendant cabin temperature
control for zone 1, zone 2 when on the cockpit temperature selector knob the
ATT position is selected.
MCDU DATA SET MENU
Take off data set menu enables pilot selection of the ECS system for take off,
ON or OFF.
FEET VALVES SELECTOR
Purely mechanical control of the feet valves to direct more warm air to the
pilot feet.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
INDICATION PANELS
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FOR TRAINING PURPOSES ONLY
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
INDICATIONS
Four typed of indication are used to monitor Environmental Control System
operation:
 The EICAS provides indication of the pressurization system
parameters
 The CAS field display shows warning, caution and advisory messages
 By selecting the MFD menu bar, the ECS synoptic page will provide
system status and indications concerning the environmental control
system
 CMC messages can be viewed on the co-pilot multi-function display
by selecting maintenance on the menu bar.
TRAINING INFORMATION POINTS
Caution:
THE MODULE OR UNIT CONTAINS ELECTROSTATIC
DISCHARGE SENSITIVE (ESDS) ITEMS. OBEY THE
APPROVED INDUSTRY PRECAUTIONS WHEN YOU TOUCH,
REMOVE, OR INSERT PARTS OR ASSEMBLIES. DAMAGE
CAN OCCUR FROM ELECTROSTATIC DISCHARGE.
Caution:
DO NOT TOUCH THE ELECTRICAL PINS OF THE
CONNECTORS. DAMAGE CAN OCCUR TO THE INTERNAL
ESDS COMPONENTS.
The AMS modules must be handled using ESDS (Electrostatic Discharge
Susceptible).
The AMS controller processor modules incorporate a field-loadable software
named Black Label.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
INDICATION
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FOR TRAINING PURPOSES ONLY
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
ATA 21-20 AIR CONDITIONING DISTRIBUTION
INTRODUCTION
The air that is already pressure-regulated by the pneumatic system passes
through the two packs where duct flow and temperature are adjusted to the
required level.
At the packs outlet, temperature sensors monitor duct temperature. Before
the distribution ducts enter the pressurized area, there are ground and ram
air connections. Check valves make sure that there is no back- flow into the
packs.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
AIR CONDITIONING SCHEMATIC
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
DESCRIPTION
FLIGHT DECK SUPPLY
Air supplied to the flight deck is distributed through ducts which run along the
left-hand side of the cabin under floor area. These ducts then form a loop to
supply the following outlets and areas:
 The raiser will direct air to the rear ceiling outlets,
 from the main and the cross feed supply, air is directed to the side
windows
 The front section of the distribution loop provides display ventilation
through the piccolo duct.
The pilot and first officer positions have handle-actuated butterfly valves that
provide air for foot warming or cooling.
Normally 60% of the mixed air from the left side ECU (Environmental Control
Unit) goes to the cockpit and 40% goes to the passenger cabin through the
mixing manifold (H-duct).
Air passages located in the cockpit floor, under the pilots seats, lateral
consoles, and the control column opening let the air return to the re
circulation fans and to the aircraft outflow and pressure relief valves.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
AIR SUPPLY TO THE FLIGHT DECK
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
CABIN AIR DISTRIBUTION SYSTEM
The cabin air distribution system starts at the mixer duct. From this point the
conditioned air is distributed to the gasper system, and to the front and rear
passenger cabin sections. Ducts from the mixer duct direct air to the raisers
and to the upper plenums.
In the gasper system the air exits through the individual outlets above the
passenger seats. For the main distribution system, the air exits above and
below the overhead bins.
Return air passes to the under floor areas through "DADO" panels located
just above the floor on the fuselage side panels.
TRAINING INFORMATION POINTS
The passenger cabin distribution ducts are installed in the aircraft with tiedown straps. During removal/installation procedures you must use an
appropriate tool to install and tension the tie-down straps that attach the
cabin distribution ducts to the adjacent components and structure supports.
The ducts are made of composite material. If you do not apply the correct
tension to the tie-down straps, damage to the ducts might occur.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
CABIN AIR DISTRIBUTION SYSTEM
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FOR TRAINING PURPOSES ONLY
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
GASPER VENTILATION SYSTEM
The gasper ventilation system is supplied by air flowing from the mix manifold
through the gasper check valve. The check valve allows air flow to the front
and rear gasper ducts, and through the gasper plenum to the gasper outlets.
TRAINING INFORMATION POINTS
Caution:
TO PREVENT DAMAGE TO THE AIR CONDITIONING SYSTEM
COMPONENTS, APPLY THE ELECTRICAL POWER BEFORE
YOU APPLY THE PNEUMATIC POWER AND REMOVE THE
PNEUMATIC POWER BEFORE YOU REMOVE THE
ELECTRICAL POWER.
The gasper ducts are installed in the aircraft with tie-down straps. During
removal/installation procedures you must use an appropriate tool to install
and tension the tie-down straps that attach the gasper ducts to the adjacent
components and structure supports. The ducts are made of composite
material. If you do not apply the correct tension to the tie-down straps,
damage to the ducts can occur.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
GASPER VENTILATION SYSTEM
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FOR TRAINING PURPOSES ONLY
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
RECIRCULATION SYSTEM
Re circulation of the cabin air is controlled by two re circulation fans. The fans
draw air from the re circulation bay through glass-fibre filter elements and
direct the air back to the mixer duct.
The re circulation fans are single-speed fans driven by three-phase 115/
200V AC motors. The motors contain internal thermal protection circuits to
shut down the fan in case of an over temperature condition.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
CABIN AIR RE CIRCULATION DIAGRAM
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
RAM AIR VENTILATION SYSTEM
The ram air ventilation system allows outside ambient air to enter the flight
deck and passenger compartment when the air conditioning packs are shut
down.
The system is normally not actuated when packs are operating, and ram air
is passing through the heat exchangers to provide duct cooling.
The ram air system includes a ram air valve installed in the left ram air inlet
duct, and ram air check valve installed in the right ram air duct. The ram air
ventilation valve is a butterfly valve powered by 28 VDC. Micro switches are
provided for position indication.
The manual override feature allows manual opening and closing of the valve.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
RAM AIR VENTILATION SYSTEM
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
ATA 21-29 LOW PRESSURE GROUND SUPPLY
The low pressure ground supply consists of an air conditioning subsystem
built to receive conditioned air from a ground cart.
The LP (Low Pressure) ground connection port, ducts and valves are located
in the wing-to-fuselage fairing forward panel area. Two small ducts connect
the LP ground connection port (nipple) to the aircraft air conditioning pack
outlet ducts. Two check valves prevent the air from the air conditioning packs
from leaking to the nipple in normal operation.
TRAINING INFORMATION POINTS
Warning: DO NOT TOUCH THE AIR-CYCLE MACHINE OR ITS
COMPONENTS IMMEDIATELY AFTER THE OPERATION
STOPS. INJURIES CAN OCCUR TO YOU BECAUSE OF THE
HIGH TEMPERATURE.
Warning: STAY AT A SAFE DISTANCE FROM THE ENGINE AIR INTAKE
AND EXHAUST AREAS DURING THE START AND GROUND
OPERATIONS. THESE AREAS ARE DANGEROUS. IF YOU
STAY NEAR THEM, INJURIES CAN OCCUR TO YOU.
LP ground connection ducts: connect the nipple to the pack outlet ducts and
conduct the airflow from the external source.
LP ground connection check valves: are five inch diameter twin petal check
valves, which are located in the low pressure ground connection ducts.
The two LP ground check valves, one for each duct, prevent LP air from
exiting the aircraft through the LP ground connection port, when the ECS
(Environmental Control System) packs are in use.
The conditioned air coming from the ground cart through the nipple, ducts
and the check valves goes into the pack outlet ducts to the aircraft
distribution system.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
LOW PRESSURE SUPPLY
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
COMPONENTS
DISTRIBUTION DUCTS
FUSELAGE DRAIN VALVE
The distribution duct system has the following main sections:
 mixer duct,
 cockpit distribution ducts,
 cabin front zone distribution ducts and
 cabin rear distribution ducts.
The valve assembly consists of a Valve retainer that is fastened to the inner
fuselage wall. A valve housing is inserted (or removed) through this hole from
the aircraft exterior. The valve housing consists of a pre- assembled valve,
which is made of piston-like reciprocating cylinder, a helical compression
spring and an aperture-retaining cap.
The ducts are made of composite material and are protected by adhesive
tape to retain thermal energy.
When the valve is in the OPEN position, collected condensed water (or
whatever other fluid inside the fuselage) and air are free to flow overboard
through cutouts in the valve housing, and out the open valve (between the
upwardly biased valve member and valve seat on the inside surface of the
bottom of the valve housing).
The ducts are designed to handle temperatures from -40∞C to +70∞C. (8)
Duct connections are elastomeric sleeves or metal clamps, with ports
provided to drain condensation.
Training Information Points
FUSELAGE THERMAL ACOUSTIC INSULATION
Caution:
This material has the following functions:
 Reduce heat transmissions through fuselage for thermal comfort.
 Noise attenuation through fuselage.
It is made of fiberglass and non-hygroscopic blankets. The blankets are
involved by a thin, film for mechanical protection and better workmanship,
forming thus a bag. Each bag has a breather, always facing down, to allow
for pressure equalization during aircraft operation. Placement of breather
intends to prevent water penetration into the bags.
TO PREVENT DAMAGE TO THE AIR CONDITIONING SYSTEM
COMPONENTS, APPLY THE ELECTRICAL POWER BEFORE
YOU APPLY THE PNEUMATIC POWER AND REMOVE THE
PNEUMATIC POWER BEFORE YOU REMOVE THE
ELECTRICAL POWER.
The cockpit ducts are installed in the aircraft with tie-down straps. During
removal/installation procedures you must use an appropriate tool to install
and tension the tie-down straps that attach the ducts to the adjacent
components and structure supports. The ducts are made of composite
material. If you do not apply the correct tension to the tie-down straps, the
ducts might be damaged.
The pressurized zone is internally insulated with this material, except in the
zones where frame systems installations required differently and in some
case the insulation is not installed for specific purposes (for example E-Bays).
The lower part of electronic bays has a non-insulated area of 41.4ft2 for the
mid E-Bay, 42.3ft2 for the forward E-Bay and 15ft2 for the aft E-Bay where
neither acoustic nor thermal requirements is needed for occupants.
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FOR TRAINING PURPOSES ONLY
Page: 32
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
THE DISTRIBUTION DUCT SYSTEM
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 33
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
MIXER
The mixer is a composite component, which has no valves or moving part
inside. It has the following input ducts;
 Flow from PACK 1
 Flow from PACK 2
Pack flow is controlled by the AMS controlled, modulating the flow control
valve. Flow and therefore valve position based on available bleed source and
users.
 Flow from RECIRC FAN 1
 Flow from RECIRC FAN 2
Fans are normally selected on for the flight. Can be selected of or in case of
failure RAM AIR VALVE will automatically open and ensure cabin ventilation
or in case DUMP has been selected on the Pressurization panel SMOKE
REMOVAL will be initiated.
The total air flow entering the flight deck, the cabin compartments and the
gaspers is made up of approximately 50% fresh air and 50% re circulated air.
 Hot air from TRIM VALVE 1 (optional)
 Hot air from TRIM VALVE 2 (optional)
Mixer can receive hot air from RH engine supply via TRIM VALVE 1 or 2 but
never from both at the same time.
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 34
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
MIXER
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 35
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
RECIRCULATION FANS
TRAINING INFORMATION POINTS
The re circulation fan is a 7.25 in diameter single-speed mixed flow fan. Each
aircraft is provided with two re circulation fans.
Caution:
The fan has the following features:
 The fan wheel is contained in a cylindrical aluminum housing.
 It incorporates a twin flapper check valve design to prevent flow in
reverse direction.
 It is driven by a three-phase 115/200 VAC, 400 Hz motor.
 It contains an internal thermal protection circuit which is used to shut
down the fan in the event of an over temperature condition.
BE CAREFUL WHEN YOU DO MAINTENANCE ON THE
RECIRCULATION BAY. DAMAGE TO THE RECIRCULATION
AIR FILTER CAN OCCUR.
Each duct-to-duct interface consists of a bead, a mating elastomeric endconnection which is an integral part of the duct and a tie-down strap. The
connection is formed by sliding the elastomeric cuff over the bead and
clamping the joint using the tie-down strap. There must be a distance of
approximately 1.5 in between the bead and the cuff end to provide space for
the correct attachment of the tie-down strap. There must be no signs of folds
or wrinkles on the cuff.
RECIRCULATION FAN FILTER
The HEPA (High Efficiency Particulate-Air) type filters, located before the
recirculation fans remove 99.999% of the bacteria and viruses produced by
the passengers and airborne dust and particulates. The recirculation fan filter
assembly consists of an 11.5 in diameter cylindrical glass-fiber filter element
which is encased in a protective aluminum grid. The filter is mounted on a
bracket in line with both the left and right circulation fans (two per aircraft).
The filters cannot be bypassed and become more efficient with increased
service life.
During removal/installation procedures you must use an appropriate tool to
install and tension the tie-down straps that attach the recirculation ducts to
the adjacent components and structure supports. The ducts are made of
composite material. If you do not apply the correct tension to the tie-down
straps, the ducts might be damaged.
The fan filter has the following features:
 An upper-and-lower composite flange connects the filter element and
protective grid as one assembly.
 A rubber gasket is mounted on the lower flange to provide the sealing
mechanism for installation on the aircraft.
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 36
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
SMOKE DETECTOR
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 37
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
EMERGENCY RAM AIR VALVE
RAM AIR CHECK VALVE
The AMS controller controls the emergency ram air valve.
The emergency ram-air ventilation system allows outside ambient air to enter
the cockpit and passenger cabin when the air conditioning pack is shut down.
The emergency ram-air check-valve is a five inch diameter twin petal check
valve which is located in the right pack ram air inlet ducting. The emergency
ram-air check-valve does not require electronic control. It will be open
whenever the cabin ECS (Environmental Control System) cooling pack is off
and the pressure in the ram air circuit is greater than cabin pressure. The
valve has:
 Two aluminum check valve petals retained in the check valve housing
by a common hinge pin;
 A wire retention spring used to hold the check valve petals in the
closed position;
 A mechanical bar type stop.
The emergency ram air valve is commanded open whenever the ram air
valve is commanded open whenever both packs are commanded off or failed
off, the aircraft is below 25000 ft and is weight off wheels.
During smoke removal both packs will be shut off, and therefore the ram air
valve and the ram air check valve will open. EICAS advisory and CMC
messages are provided if one or more of the valves fail closed.
The synoptic page shows the ram air valve in green when the valve is open,
and in red when the ram air valve is closed.
The emergency ram-air valve is a 5-inch diameter electrically-actuated
butterfly valve. The valve is opened and closed by a 28 VDC (Volt Direct
Current) electric actuator which rotates a splined butterfly shaft. This shutoff
valve also contains a manual actuation lever which can be used to manually
position the valve in the event of actuator electrical failure. The valve and
actuator require no lubrication or servicing.
The emergency ram-air valve is tested each time the AMS (Air Management
System) controller is powered up. The AMS controller commands the valve
full open and then closed. This valve has position switch feedback for
position indication. The EICAS (Engine Indicating and Crew Alerting System)
message RAM AIR FAULT will be displayed if the valve has failed in the
closed position.
The emergency ram-air valve actuator moves the emergency ram-air valve
through a movable arm. When ram air flows to the heat exchanger, the flow
to the ram air duct closes, and vice-versa.
The electric actuator utilizes a 28 VDC motor which acts on a worm type gear
and wheel assembly to rotate the valve shaft. The actuator contains two sets
of micro switches which are used for valve open/ close indication and
actuator over travel protection.
The linear actuator electrical travel is limited by two limit switches, one in the
retracted position and the other in the extended position.
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 38
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
EMERGENCY RAM AIR VALVE
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 39
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
OPERATION
RECIRCULATION FANS
The recirculation fans are controlled by the Air Management System
controller, through the selector switch located in the cockpit. They are
powered by the Secondary Power Distribution Assembly2.
During single pack condition:
 In flight, only with left pack is OFF AND the aircraft is in the AIR AND
airspeed > 50 knots (left fan only), the left recirculation fan should be
commanded OFF
 On ground, only with left pack is OFF AND the aircraft is on the
ground AND right pack is ON, the left recirculation fans should be
commanded OFF
The fans are commanded ON when the RECIRC switch is in the AUTO
position (latched). Exceptions are:
 Both fans will be commanded OFF if the Cabin Pressure ControlSystem dump switch is latched.
 Both fans will be commanded OFF if smoke is detected in the
recirculation bay by the recirculation-bay smoke detector or the
smoke detected signal is invalid or the smoke detector is failed.
The AMS controller will generate an EICAS message RECIRC SMOKE when
the smoke alarm signal is received for the recirculation-bay smoke detector.
 Both fans will be commanded OFF if the cargo-bay fire signal is true
or invalid;
 Both fans will be commanded OFF as a function of ambient
temperature and altitude while on the ground, during the pull-up
mode, when the APU is supplying bleed air as the left bleed source;
 The fans will also be commanded OFF under over temperature
conditions.
 The right recirculation fan may remain on when the cabin pack is OFF
On the ECS synoptic page the re circulation fans will be indicated in green
when they operate and in red if they are switched off.
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 40
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
RECIRCULATION FANS
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 41
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
RAM AIR VALVE
The emergency ram-air valve is commanded open by the AMS controller
when both cooling packs are commanded or failed off and the aircraft altitude
is less than 25000 ft.
When the emergency ram-air valve is commanded open, fresh air entering
the left ram air inlet flows through the valve, bypassing the air conditioning
pack, to provide ventilation for the flight deck. This provides additional fresh
air ventilation.
On the ground, the valve will be closed if the aircraft speed is less than 50
kts. In order to avoid unnecessary message, the emergency ram-air valve is
also commanded closed when the aircraft is in Ground Service Mode.
The ram-air ventilation system is also used for emergency cockpit smoke
removal. If there is evidence of smoke in the cockpit, the flight crew will latch
the cabin pressure-control-system dump-switch.
Upon receipt of the dump switch signal the AMS controller will command both
the left and right pack flow control valves closed. The left and right
recirculation fans will be commanded off to eliminate recirculation of cockpit
air flow.
The forward electronics compartment backup ventilation fan will be
commanded on to increase ventilation flow through the cockpit area. The
emergency ram-air valve will be commanded open. These actions will permit
the flow of fresh air through the emergency ram-air valve to clear smoke in
the cockpit area. Fresh air will also flow through the emergency ram-air
check-valve to equalize pressure in the mixing duct and provide emergency
ventilation for the passenger cabin zones.
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 42
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
RAM AIR VALVE OPERATION
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 43
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
SMOKE REMOVAL
The ram ventilation system is also used for cockpit smoke removal.
Flight crew will depress cockpit DUMP switch as an emergency procedure for
cockpit smoke removal. When the dump switch is depressed the CPCS
(Cabin Pressure Control-System) will depressurize the cabin at a rate of 2000
ft/min. The AMS (Air Management System) controller will then shut down
both air conditioning packs, turn off both re circulation fans and open the
emergency ram air check valve. This will allow fresh air to flow through the
cockpit.
TRAINING INFORMATION POINTS
Warning: DO NOT GO NEAR THE OPENING OF THE HIGHPRESSURE
GROUND CONNECTOR DUCT WHEN YOU PRESSURIZE THE
PNEUMATIC DUCT. THE BLEED AIR THAT COMES OUT OF
THE OPENING CAN CAUSE INJURY TO PERSONS.
Warning: DO NOT TOUCH THE DUCTS OR COMPONENTS OF THE AIR
BLEED SYSTEM IMMEDIATELY AFTER THE SYSTEM STOPS
ITS OPERATION. THE HIGH AIR TEMPERATURE CAN CAUSE
INJURY TO PERSONS.
Caution:
MAKE SURE THAT THE RAM AIR INLET DUCTS AND THE
NACA SCOOP DUCTS ARE ALIGNED. IF NOT, DAMAGE TO
THE BELLOWS CAN OCCUR.
There must be no twists or bends on the bellows. In addition to that, the ducts
and bellows must be aligned with the adjacent components. This is to avoid
damage to the ducts installation and to the air conditioning packs during
operation.
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 44
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
SMOKE REMOVAL
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 45
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
DIAGNOSTIC AND TESTS
The recirculation bay smoke detector is tested by the AMS controller using
the recirculation bay smoke detectors automated BIT function. The BIT is
performed whenever the AMS controller is powered up (after shut down) and
two minutes after each aircraft landing. The AMS controller sends a test
signal to the recirculation bay smoke detector that causes the recirculation
bay smoke detector to perform an internal BIT: The recirculation bay smoke
detector BIT sequence includes fan current monitoring and a test of the
smoke detecting and alarm capability. If the recirculation bay smoke detector
does not pass the BIT sequence the AMS controller will generate the EICAS
message RECIRC SMK DET FAIL to alert the flight crew that the
recirculation bay smoke detector is inoperative.
In addition, continuous BIT monitors sets the RECIRC SMK DET FAIL EICAS
Message if the recirculation bay smoke detector has been failed due to an
electrical power supply lost (open circuit) or Smoke Detected signal is not
valid for 10 or more seconds.
The emergency ram air ventilation valve is tested each time the AMS
controller is powered up. The AMS controller commands the valve full OPEN
and then CLOSED. This valve has position switch feedback for position
indication. EICAS message RAM AIR FAULT will be displayed if the valve
has failed in the CLOSED position.
System reset
System reset can be performed with the channel transfer preconditions.
Reset will be only successful when there are no active fault conditions.
EICAS and Maintenance Messeges should be checked in ATA 36,21,30 and
35 chapters.
Smoke test IBIT
Test can be performed when , A/C is WONW, Channel in control and smoke
detector signal is valid. Only on A/C with animal bay optional fan and shut off
valve installed.
RECIRC fan parameters
Beside recirc fan status and parameters the page also allows to view emrg
ram air valve status and discrete inputs from cockpit switchesRAM AIR VALVE
IBIT can be performed whem WONW, channel in control, Aircraft speed
below 50knots conditions are true and Pack is selected off-
Channel Transfer
During the test the valve will be commanded open and closed.
Channel status and therefore channel transfer is continuously monitored.
AMS status page
Preconditions are:
 WON W
 Airspeed below 50knots
 Channel not in control already
Allows to view FADEC commands, AMS system valves positions and APU
bleed valve position.
Please do not forget and it is valid for all IBITS: during test AMM II
operational or functional test instructions has to be followed.
Beside all above the channel should be healthy inclusive no fault on
processor, control input output and motor drive card. Also important and
condition no pressure sensor failure.
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 46
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
CMC TESTS
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 47
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
ATA 21-26 AVIONICS COMPARTMENT
INTRODUCTION, DESCRIPTION
The avionics compartment ventilation system incorporates forward and
middle compartments.
The main function of the forward avionics compartment ventilation system is
to provide a reliable ventilation source that will maintain a safe temperature in
the forward avionics compartment. The forward avionics compartment
ventilation system utilizes three 4.5 in diameter single- speed fans to pull air
from the avionics compartment to the re circulation area.
The fans contain an integral check valve to prevent reverse flow when the fan
is not in use.
The fans are connected in parallel to a common supply duct. An electronic
flow sensor is mounted in the main ventilation supply duct and is used for
system health monitoring.
The main function of the middle avionics compartment ventilation system is to
provide a reliable ventilation source that will maintain a safe temperature in
the middle avionics compartment. The middle avionics compartment
ventilation system utilizes two single-speed fans and one 2- speed fan to pull
air from the middle avionics compartment to the re circulation area.
The fans contain an integral check valve to prevent reverse flow when the fan
is not in use. The fans are connected in parallel to a common distribution
duct. An electronic flow sensor is mounted in the main ventilation duct and is
used for system health monitoring.
The aft avionics compartment does not have a dedicated fan. A duct is routed
from the aft avionics compartment to the middle avionics compartment inlet
duct.
This duct draws air from the passenger cabin through the aft avionicscompartment area using the middle avionics compartment fan as a driven
source. This duct improves the performance of the aft avionics- compartment
ventilation and also the smoke containment in that area.
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 48
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
FORWARD ELECTRONIC BAY
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 49
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
COMPONENTS
FORWARD AVIONICS COMPARTMENT FAN
The forward avionics compartment fan is a 4.5 in diameter single-speed axial
flow fan, weighing 4.5 lb with an overall length of 6.5 in,and produces a
volumetric flow rate of 224 ft3/min. The fan wheel is contained in a cylindrical
aluminium housing which incorporates a twin flapper check valve design to
prevent flow in the reverse direction.
The fan is driven by a 3 - phase 115/200 VAC 400 Hz motor. The motor
contains an internal thermal protection circuit which is used to shut down the
fan in the event of an over temperature condition. Maintenance of the fan is
on condition.
FORWARD AVIONICS COMPARTMENT VENTILATION DUCTS
A common supply duct has three fans that are connected in parallel to it. An
electronic flow sensor is mounted in the main ventilation supply duct and is
used for system health monitoring. The ducts are made of composite
materials.
FORWARD AVIONICS COMPARTMENT FLOW SENSOR
The forward avionics compartment flow sensor consists of a CRH (Constant
Resistance Heating) element and a platinum RTD (Resistance Temperature
Device) mounted in a stainless steel probe. A constant voltage is applied to
heat the CRH element to a known value.
The CRH element temperature and electrical resistance will change with
variations in mass flow rate. The RTD element measures the ambient air
temperature in the duct.
The AMS (Air Management System) controller uses the CRH element
resistance changes, along with the ambient temperature from the RTD
element to calculate a local mass flow rate in the duct.
If the local mass flow rate falls below a certain level (indicating no duct flow),
the AMS controller, through the EICAS (Engine Indicating and Crew Alerting
System), alerts the flight crew of a low flow condition.
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 50
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
FAN FAILURES
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 51
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
MIDDLE AVIONICS BAY FANS
The centre avionics bay ventilation system contains fans that pull air from the
passenger cabin under floor areas through the centre avionics compartment,
and exhaust the air into the re circulation bay.
The motor contains an internal thermal protection circuit which is used to shut
down the fan in the event of overtemperature. Maintenance of the fan is on
condition.
The two single-speed fans and one two-speed fan are connected in parallel
to a common distribution duct, and contain integral check valves in order to
prevent reverse flow. A sensor mounted in the fan supply duct provides
system health monitoring.
MIDDLE AVIONICS COMPARTMENT FLOW SENSOR
The middle avionics compartment flow sensor consists of a CRH element
and a platinum RTD element collocated in a stainless steel probe. A constant
voltage is applied to heat the CRH element to a known value.
MIDDLE AVIONICS COMPARTMENT FAN
The middle avionics compartment single-speed fan is a 5.25 in diameter axial
flow fan, weighing 6.1 lb with an overall length of 7.25 in, and produces a
volumetric flow rate of 547 ft3/min.
The fan wheel is contained in a cylindrical aluminum housing which
incorporates a twin flapper check valve design to prevent flow in the reverse
direction. The fan is driven by a 3-phase 115/200 VAC 400 Hz motor.
The CRH elements temperature and electrical resistance will change with
variations in mass flow rate. The RTD element measures the ambient air
temperature in the duct.
The AMS controller uses the CRH element resistance changes, along with
the ambient temperature from the RTD element to calculate a local mass flow
rate in the duct. If the local mass flow rate falls below a certain level
(indicating no duct flow) the AMS controller will alert the flight crew of a low
flow condition using the EICAS
The motor contains an internal thermal protection circuit which is used to shut
down the fan in the event of overtemperature. Maintenance of the fan is on
condition.
MIDDLE AVIONICS COMPARTMENT FAN (2-SPEED)
The middle avionics compartment 2-speed fan is a 5.25 in diameter axial flow
fan, weighing 6.7 lb with an overall length of 7.25 in, and produces a
volumetric flow rate of 370 ft3/min in low speed operation and 547 ft3/min in
high speed operation.
The fan wheel is contained in a cylindrical aluminum housing which
incorporates a twin flapper check valve design to prevent flow in the reverse
direction. The fan is driven by a 3-phase 115/200 VAC 400 Hz motor.
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 52
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
FAN FAILURES
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 53
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
OPERATION
FORWARD AVIONIC COMPARTMENT
The forward avionics compartment architecture consists of one flow sensor,
two fans for normal operation and one emergency backup fan. During normal
system operation, the left fan operates and the right and the emergency
backup fan (center) remain in standby mode. If there is a failure of the left
fan, the right fan is commanded on. If there are failures of both left and right
fans, the emergency fan (center) is commanded on. This also turns on, in low
speed mode, the emergency backup fan in the middle avionics compartment.
The system utilizes an electronic flow sensor, installed on the ventilation duct,
to detect a low flow condition. The low flow sensor switch set point is
adjusted for the flow of one fan in the forward avionics compartment.
Hot Day Ground Operation
For ground operation with the ambient temperature above 86 Deg F (30 Deg
C) both Fan 1 and Fan 2 will be turned on to meet a two fan flow threshold.
Fan 3 will be in standby mode and will be turned on only if Fan 1 or Fan 2
has failed.
The FWD E-BAY FANS FAIL messages shows on the EICAS if:
 the two fans for normal operation (left and right) are failed AND the
aircraft is on ground, OR;
 The emergency backup fan is failed AND the aircraft is on ground,
OR;
 The flow sensor is failed AND the aircraft is on ground, OR;
 The flow sensor indicates that there is NOT at least one fan operating
(low-flow sensor reading),OR;
 All three fans are failed AND the aircraft is in flight.
A single fan failure results in only one CMC (Central Maintenance Computer)
message. It is important to note that the forward avionics compartment
ventilation system can maintain adequate compartment cooling with one fan
operational.
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 54
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
FORWARD ELECTRONIC FAN OPERATION
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 55
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
MIDDLE AVIONICS COMPARTMENT
The middle avionics compartment architecture consists of one flow sensor,
two single-speed fans for normal operation and one 2-speed emergency
backup fan.
A single fan failure will result in only one CMC message. It is important to
note that the middle avionics compartment ventilation system can maintain
adequate compartment cooling with one fan operational.
During normal system operation, fan 1 (left) operates and fan 2 (center) and
the emergency backup fan (right) remain in standby mode. If there is a failure
of fan 1, fan 2 is commanded on. If there are failures of both fan 1 and 2, the
emergency backup fan is commanded on in high speed mode. The system
utilizes an electronic flow sensor, installed in the ventilation duct, to detect a
low flow condition. The low flow sensor switch set point is adjusted for the
flow of one fan in the middle avionics compartment.
Note:
Hot Day Ground Operation
For ground operation with the ambient temperature above 86 Deg F (30 Deg
C) both Fan 1 and Fan 2 will be turned on to meet a two fan flow threshold.
When the RAT is deployed, the middle avionics compartment
emergency fan uses the low speed setting to minimize power
consumption.
TRAINING INFORMATION POINTS
The avionics compartment ducts are installed in the aircraft with tie-down
straps. For removal/installation procedures, you must use an appropriate tool
to install and tension the tie-down straps that attach the avionics
compartment ducts to the adjacent components and structure supports. The
ducts are made of composite material. Damage to them can occur if you do
not apply the correct tension to the tie-down straps.
Fan 3 will be in standby mode and will be turned on (high speed) only if Fan 1
or Fan 2 has failed.
The CENTER E-BAY FANS FAIL message shows on the EICAS if:
 The two fans for normal operation (left and center) are failed AND the
aircraft is on ground, OR;
 The emergency backup fan (right) is failed AND the aircraft is on
ground, OR;
 The flow sensor is failed AND the aircraft is on ground, OR;
 The flow sensor indicates that there is NOT at least one fan operating
(low-flow sensor reading), OR;
 All three fans are failed, the aircraft is in flight AND the RAT (Ram Air
Turbine) is not deployed.
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 56
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
MIDDLE ELECTRONIC BAY
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 57
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
DIAGNOSTIC AND TEST
E-Bay fans in the forward and mid E-Bays are continuously monitored by the
AMS controller using load current monitoring and overheat detection. E-Bay
flow sensors are also used to verify that there is adequate airflow in the EBay ventilation duct. In addition, the E-Bay fans in the forward and mid EBays are checked for proper operation each time the AMS controller is
powered up, and two minutes after each aircraft landing. This BIT is
automatically initiated by the AMS controller to ensure that each fan is
operational and is capable of providing adequate airflow. This test will detect
fan failures that are not detected by continuous load current monitoring.
During this power up/ post landing fan operational test the AMS controller
commands only one E-Bay fan on in each E-Bay and uses the E-Bay flow
sensor to verify that the fan is operating. This test is performed on each fan. If
all the fans in a common electronics bay (forward or mid) do not meet the
minimum flow requirements of this test, the AMS controller will determine that
the E-Bay flow sensor in the associated bay has failed.
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 58
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
DIAGNOSTIC AND TEST
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 59
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
FORWARD CARGO COMPARTMENT VENTILATION
INTRODUCTION, DESCRIPTION
The forward cargo compartment ventilation system draws air from the cabin
underfloor area by means of a single fan, and exhaust the air through the
cargo compartment shut-off valve into the re circulation bay area to the
outflow valve.
During normal operation the fan is operating, and the shut-off valve is open
and monitored by the AMS controller. In case of fire, the fan is turned off and
the valve is immediately closed.
A check valve ensures that there is no airflow toward the passenger
compartment.
Note:
This cargo compartment ventilation system is optional.
ISSUE 1, 24 Sep 2014
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
FORWARD CARGO COMPARTMENT
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
COMPONENTS
FORWARD CARGO COMPARTMENT FAN
The forward cargo compartment fan is a 4.5 in diameter single-speed axial
flow fan. The fan is driven by a 3-phase 115/200 VAC 400 Hz motor. The
motor contains an internal thermal protection circuit which is used to shut
down the fan in the event of an over temperature condition. The fan wheel is
contained in a cylindrical aluminium housing.
FORWARD CARGO COMPARTMENT CHECK VALVE
The forward cargo compartment check valve is a 3.5 in diameter dual- flapper
check valve. The valve is mounted downstream of the forward cargo
ventilation fan in the forward cargo compartment supply duct.
FORWARD CARGO COMPARTMENT SHUT OFF VALVE
The forward cargo compartment shut off valve is a 3.5 in diameter pneumatic
actuated valve. The valve is mounted in the forward cargo ventilation system
outlet duct and utilizes a 28 VDC (Volt Direct Current) solenoid for open/close
function.
FORWARD CARGO COMPARTMENT VENTILATION DUCTS
Air is distributed to the forward cargo compartment by underfloor ducts, on
the LH side of the cargo compartment (upstream and downstream of the fan)
and one in the right aft bulkhead of the cargo compartment.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
FWD CARGO COMPARTMENT
ISSUE 1, 24 Sep 2014
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Page: 63
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
OPERATION
TRAINING INFORMATION POINTS
The function of the forward-cargo-compartment ventilation system is to
provide adequate airflow in the cargo compartment to support the
transportation of live animals. The AMS controller determines if the aircraft is
equipped with the forward-cargo-compartment ventilation system via the
aircraft configuration inputs. During all normal aircraft operating conditions,
the forward-cargo-compartment ventilation fan is commanded on and the
forward-cargo-compartment exhaust valve is commanded open. The fan is
commanded off and the exhaust valve is commanded closed in response to a
fire in the cargo compartment as reported by the cargo compartment fire
extinguishing system
Warning: TO CLOSE THE CARGO DOOR, DO NOT LET IT FALL FREELY
TO PREVENT DAMAGE TO MATERIAL AND INJURY TO
PERSONS.
The cargo compartment ducts are installed in the aircraft with tiedown straps.
On removal/installation procedures you must use an appropriate tool to install
and tension the tie-down straps that attach the cargo compartment ducts to
the adjacent components and structure supports. The ducts are made of
composite material. Damage to them can occur if you do not apply the
correct tension to the tie-down straps.
The CRG FWD VENT FAIL message will display on the EICAS (Engine
Indicating and Crew Alerting System) any time the forward cargocompartment fan is failed ON or the forward cargo-compartment shutoff valve
is failed OPEN. It is also required that there is an associated forward-cargocompartment fire signal, or smoke detected, or either one of these signals
invalid to set the message. This message is intended to inform the crew that
a fire in the cargo compartment may possibly not be able to be extinguished
(inability to retain Halon).
The CRG FWD VENT FAIL message will also be displayed on the ground if
the fan is failed OFF or the shutoff valve is failed CLOSED.
This will allow the crew to remove the live cargo prior to the flight. It is
important to highlight that, in this condition, the CRG FWD VENT FAIL
message will not be latched and it will be cleared once the conditions are
corrected. For any other condition, the CRG FWD VENT FAIL message is
latched.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
OPERATING LOGIC
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
DIAGNOSTIC AND TEST
The forward cargo compartment shutoff valve is tested each time the AMS
controller is powered up. The AMS controller commands the valve full OPEN
and then CLOSED. This valve has position switch feedback for position
indication. EICAS message CRG FWD VENT FAIL will be displayed if the
valve has failed in the OPEN position.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
DIAGNOSTIC AND TEST
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 67
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
ELECTRONIC RACK VENTILATION SYSTEM
INTRODUCTION
The electronic-equipment-rack ventilation system provides airflow for cooling
of nonessential electronic equipment installed in a dedicated equipment rack.
In the event of smoke resulting from failure of electronic equipment, the rack
ventilation system provides means to discharge the smoke overboard.The
electronic-equipment-rack is installed in the lower compartment, behind the
aft partition of the aft cargo compartment.
The shelves of the rack contain the several units required for the proper
functioning of the in-flight entertainment system. Some of these units require
forced ventilation, supplied by a dedicated and independent ventilation
system, in order to minimize effects on air-conditioning distribution,
pressurization and smoke management.
The rack ventilation system comprises:
 One electric-motor-driven fan
 An overboard air-discharge port
 Two electric-motor-driven air shutoff valves
 One smoke detector
 One airflow switch
 Three airflow-limiting venturis
 Associated air collection and conveyance ducts.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
ELECTRONIC RACK VENTILATION LAYOUT
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Page: 69
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
DESCRIPTION
Plenums and ducts collect air from the rack and discharge it overboard forced
by a fan (on-ground) or by cabin differential pressure through a venturi (inflight).
The discharge duct system splits into three branches and later joins together
to form a common exhaust duct. The branches are called: ground line, vent
line and bypass line. The ground line has an electric- motor-driven air shutoff
valve. The ground valve is always open on ground when the fan is ON. It
closes in flight to prevent excessive flow leakage. The vent line is the main
path for the ventilation flow in flight. It contains an electric-motor-driven air
shutoff valve and a flow limiting venturi. The vent valve is always open,
except under certain conditions when evacuation of smoke generated in
other aircraft regions could be affected. The bypass line is always open to
ensure a minimum amount of cooling flow, whenever the vent valve is closed.
It contains a flow-limiting device to prevent excessive flow leakage that could
jeopardize the smoke containment in other areas of the airplane. An
additional venturi is installed in the common exhaust duct, downstream of the
valves. Its purpose is to minimize the impact on the cabin pressurization
control system. The venturi is sized to ensure that cabin pressure remains
below the “HI CABIN” indication set point, even in single-pack mode with the
ground valve failed open.
There is also an airflow switch used to detect loss of cooling flow. Exhaust air
or smoke is captured from the upper part of the rack and discharged
overboard through a dedicated fuselage port located at the RH (Right-Hand)
side, aft part of the aircraft fuselage, opposite to the vacuum and waste
fuselage port. The cooling air is enclosed and does not enter the cargo
compartment. It is totally exhausted overboard on the ground and in flight.
Control function, fault indication, and testing of the electronic-equipment-rack
ventilation system operation is accomplished by dedicated electrical circuits
that are independent of other aircraft control circuits.
A smoke detector is installed in the rack ventilation duct. In the event of
smoke resulting from failure of electronic equipment, the smoke detector
generates an EICAS (Engine Indicating and Crew Alerting System) message
for the crew, and automatically shuts down the electronic equipment rack.
The pilot is also required to manually shut off the rack as an added
precaution.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
COMPONENTS VIEW
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 71
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
COMPONENTS
AIRFLOW SWITCH
The airflow switch is a flow-sensing unit that uses thermal dispersion
technology where two platinum RTD (Resistance Temperature Detector) are
located in the airflow element. It is a solid state unit powered by 28 VDC (Volt
Direct Current). The airflow switch is installed in the rack exhaust-air
discharge-line (upstream the smoke detector) and has the function of
protecting the electronic equipment from an overheat condition due to lack of
air cooling. It is only deactivated (without shutting down the system) during an
aircraft single pack operation. At this time, both shutoff valves are closed and
the minimum required airflow to cool the rack is obtained through the bypass
line.
FAN
The function of the fan (brushless type) is to provide ventilation to the
electronic equipment rack when the aircraft is on the ground. The fan draws
air from the rack and discharges it overboard through the ground and vent
shutoff valves. The ventilation fan is of the 4.5 in diameter, single speed and
axial flow type. It is driven by a 3-phase 115/200 VAC/ 400 Hz motor. The
motor contains an internal thermal protection circuit which is used to shut
down the fan in the event of an overtemperature condition. The fan wheel is
installed in a cylindrical aluminium housing. The fan is attached to a structure
support and stays on aircraft during the rack removal. A rubber flexible sleeve
makes the connection to the exhaust duct of the rack and absorbs excessive
vibration.
VENTILATION DUCTS
The air/smoke extracted from the electronic equipment rack passes the fan
and reaches the shutoff valves through a set of 4.5 in diameter aluminium
ducts. Then the air/smoke is directed to the atmosphere through a vent duct
and a fuselage port located at the right hand side of the fuselage, behind the
aft avionics compartment.
ISSUE 1, 24 Sep 2014
The 3 in diameter vent duct is also made of aluminium and runs from the
shutoff valves to a 2.5 in diameter vent port at the right side of the fuselage
skin. The vent duct has an upward loop to avoid de-icing fluids ingestion and
water ingression during ditching. A venturi in the overboard exhaust duct
prevents excess loss of cabin pressure in case of a duct failure.
A duct bypasses the ground shutoff valve and prevents excessive loss of
cabin pressure in case of duct failure. It also keeps a minimum required
airflow for the rack cooling when the vent shutoff valve is closed due to
smoke detection in the air conditioning system (basically in the recirculation
bay), single pack operation or for dispatch ability when one pack is
inoperative.
SHUTOFF VALVES
The ground and vent shutoff valves are identical. They are attached to the aft
floor panel (aft avionics compartment) close to the aft pressure bulkhead.
These valves are of the electric-motor-driven butterfly type and consists of
two major subassemblies: an actuator and a butterfly valve. The actuator
assembly controls the position of the valve. It comprises of an electric motor,
a gear train, position control/indication switches, an electrical connector, and
a housing.
The actuator moves the valve to each of the two desired discrete positions,
fully closed and fully open, based on command from the aircraft. The motor is
a precision, aircraft-quality, brush-type 28 VDC permanent magnet.
The valves contain limit switches that control the motor and provide valve
position indication.
FOR TRAINING PURPOSES ONLY
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
COMPONENTS VIEW
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
OPERATION
During ground operation, the fan draws the air from the underflow
compartment through the rack equipment and exhausts it to the outside. The
ground valve and vent valve are open. The airflow switch monitors the airflow
rate to ensure adequate cooling capacity for the electronic units.
During takeoff, when the TLA (Thrust Lever Angle) is moved above 60
degrees and the parking brake is released, the ventilation system is
automatically configured to the flight mode. During descent and landing, this
configuration will remain until 20 s after touchdown, when the system reverts
back to ground mode. In the flight mode, the ground valve is closed and the
fan is shut off.
The vent valve and the bypass line are open. The pressure difference
between the cabin and the outside air serves as the driver for cabin air to flow
through the rack ventilation system discharging the exhaust air to the outside.
The airflow switch monitors the airflow rate to ensure adequate cooling
capacity for the electronic units. Its signal is inhibited during flight.
FAN
During normal ground operation, the fan is commanded ON and both shutoff
valves are commanded OPEN. After takeoff or in response to a smoke
detection on ground, the fan is commanded OFF and the ground shutoff
valve is commanded CLOSED.
The fan operates on the ground even when only the ground service power
bus is available, in order to ventilate the Wireless Aircraft Unit (WAU).
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
OPERATION
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
GROUND SHUTOFF VALVE
AIR FLOW SWITCH
When the aircraft is on the ground, the normal rack ventilation system
operation uses the ambient air from the under-floor compartment. A
dedicated electric fan draws this ambient air through the rack equipments
and discharge it overboard through the ground shutoff valve.
The airflow switch is a unit installed in the rack exhaust line, upstream of the
smoke detector. The function of the airflow switch is to protect the rack
equipments from an overheat due to a lack of air cooling.
The ground shutoff valve is commanded to the open position after the
following conditions have been achieved:
 TLA < 60∞
 Time delay after WOW (Weight-on-Wheels) - 20s
 Parking brake switch - ON
 Rack power - ON
At the same time, the ground shutoff valve is commanded OPEN, the fan is
commanded ON.
Upon detection, the signal from the switch is sent via relays to the SPDA
(Secondary Power Distribution Assembly), which then automatically removes
the electrical power to the rack to protect the LRU (Line Replaceable Units).
Logic is built into the SPDA to ignore the transient conditions during
electronic-equipment-rack start up on the ground or the fan activation soon
after touch down (during landing, when the ventilation flow falls below the
flow switch “LOW FLOW” set point).
This inhibition is 70 s at system start-up and 40 s after touch down. The flow
switch signal is also inhibited in flight.
The ground shutoff valve is commanded to the closed position after the
following conditions have been achieved:
 TLA > 60∞
 Parking brake switch - OFF
At this time, the electrical power is removed from the fan.
A bypass line around the ground shutoff valve allows a minimum airflow
required for the rack equipment cooling when the aircraft is dispatched with
single pack operation and the vent shutoff valve is in the closed position.
VENT SHUTOFF VALVE
The vent shutoff valve is normally in the OPEN position. In flight conditions,
the cabin differential pressure draws air from the rack and discharge it
overboard through the vent shutoff valve and the fuselage port.
The vent shutoff valve is commanded to the closed position after the
following conditions have been achieved:
 single pack operation
 smoke detected in the recirculation bay
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 76
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
OPERATION
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 77
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
MAINTENANCE TEST PANEL
The maintenance test panel is installed in the aft electronics- compartment
rack on the right-hand side at the upper shelf. It provides a mean for testing
the smoke detector and also to verify the operation of the shutoff valves
(ground/vent). The panel also indicates failures of the smoke detector, vent
shutoff valve, ground shutoff valve and rack cooling system (fan and airflow
switch) through 4 LED (Light-Emitting Diode)s (amber color). These failure
indications are latched in order to enable the maintenance crew to evaluate
the problem on the ground. The single 3- position momentary toggle switch
(with normal central position lever-lock) provides a mean for operationally
checking the vent shutoff valve and the ground shutoff valve. When the
aircraft is on the ground, in normal operation condition, both SOV (Shutoff
Valve)s must be in the OPEN position, confirmed by the LED “OPEN”
indication illuminated in green color.
There are four failure indication LEDs (amber color) on the maintenance test
panel: vent valve, ground valve, smoke detector (auto test) and rack cooling
system (ducting, fan or airflow switch). They are intended to help the ground
crew to determine which LRU needs troubleshooting. These failure
indications are latched once they occur. The circuit breaker is installed to
permit maintenance on the applicable LRU powered by 28VDC such as:
smoke detector, airflow switch, SOVs, relays and LEDs.
The operational checks are achieved by lifting the toggle switch and moving it
UP (to test the vent valve) and DOWN (to test the ground valve). At this time
the LED “OPEN” indication will turn OFF and after a few seconds (5-8 s) the
LED “CLOSED” indication will turn ON indicating full traveling of the
applicable shutoff valve. When you release the toggle switch and locks it in
the central position, that will open the applicable shutoff valve and the LED
“CLOSED” indication will turn OFF. Consequently, the LED “OPEN”
indication will turn ON.
The AMBER LEDS TEST switch (press-to-test type), when activated, will
send a ground and indicate that all LEDs (amber) are operational. The other
five LEDs (green) can be tested during the ground and vent valve operational
checks and the smoke detector test.
The smoke detector test switch allows complete testing of the smoke
detection and indication system for the electronic equipment rack. When the
test switch is momentarily pressed, it illuminates in white color indicating that
the test has initiated. When the test is successfully completed, the LED
“PASS” indication will illuminate in green color and the “IFE RACK SMOKE”
caution message is displayed on the EICAS. At the same time, an aural
warning activated in the cockpit.
The LED RESET 2-position momentary toggle switch (with normal position
lever-lock) allows the LED “FAIL” indication (amber color) to be cleared after
the cause of the fault indication has been fixed.
EFFECTIVITY: 190:00004-00035
EFFECTIVITY: ON ACFT 190:00039-99999
The LEDS TEST switch (press-to-test type), when activated, will send a
ground and indicate that all LEDs (amber and green), except the SMK DET
PASS, are operational. The SMK DET PASS LED (green) can be tested
during the smoke detector test.
When the test switch is held pressed longer than 10 s, the auto shutdown
function is checked. In this case, the power is removed from rack
components and the IFE RACK SMOKE message is displayed on EICAS. At
the same time a aural warning is activated in the cockpit.
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FOR TRAINING PURPOSES ONLY
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
MAINTENANCE TEST PANEL OPERATION
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 79
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
DIAGNOSTIC AND TEST
MAINTENANCE TEST PANEL
The maintenance test panel is installed in the aft electronics- compartment
rack on the right-hand side at the upper shelf. It provides a mean for testing
the smoke detector and also to verify the operation of the shutoff valves
(ground/vent).The panel also indicates failures of the smoke detector, vent
shutoff valve, ground shutoff valve and rack cooling system (fan and airflow
switch) through 4 LED (Light-Emetting Diode)s (amber color).These failure
indications are latched in order to enable the maintenance crew to evaluate
the problem on the ground.
MONITORING PANEL (LEDS)
The ventilation system monitoring panel consists of 4 LEDs installed near the
G2 Galley, on the side panel, forward of the LH passenger entry- door:
 COOLING FAIL
 SMOKE DETECTOR FAIL
 GROUND VALVE FAIL
 VENT VALVE FAIL
Just like the maintenance test panel, these LEDs also indicate eventual
failures of the rack ventilation system LRU (Line Replaceable Unit)s. The
main difference is that the monitoring panel has an easier access and is
much simpler (it does not have test functions, for instance).The monitoring
panel is used for maintenance purposes only (such as troubleshooting).
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FOR TRAINING PURPOSES ONLY
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
MAINTENANCE TEST PANEL
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 81
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
ATA 21-30 PRESSURIZATION
INTRODUCTION
The Cabin Pressure Control System is designed for completely automatic
operation. The pressurization controller has two fully independent channels,
which alternate after each flight (70 seconds after touchdown). Both channels
provide a manual back up function. The system utilizes digital electronics to
communicate with the other aircraft systems via ARINC 429 buses and
discrete signals.
The Cabin Pressure Control System, in automatic mode, will control the
pressurization in the cabin to a maximum cabin altitude of 8,000ft. The
system will also control the maximum differential pressure of 8.32 psi up to
41,000ft aircraft altitude with a comfortable rate of change in climb and
descent modes. The CPCS provides two different nominal differential
pressures. For cruises below 37000 ft, the nominal differential pressure is
scheduled to 7.77 psid. For cruises above 37000 ft, the nominal differential
pressure is scheduled to 8.32 psid. These limits are achieved by modulating
the airflow through the outflow valve. Separate mechanical positive and
negative relief valves satisfy the safety relief functions.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
CABIN PRESSURE CONTROL SYSTEM
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 83
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
DESCRIPTION
CABIN PRESSURE CONTROL
The Cabin Pressure Control System includes the following components:
 The pressurization controller,
 the cabin outflow valve,
 the negative pressure relief valve and
 safety valve.
For BITE purposes and cockpit indication on EICAS, the position of the
outflow valve is taken from one channel of a dual potentiometer. Speed
control is achieved via a motor revolution counter fed by signals from the
three hall sensors in the motor.
The flight deck interface contains the pressurization control panel, including
an auto and manual selector rotary switch, the EICAS display with Cabin
Pressure Control System related messages, and the EICAS display lower
section where cabin altitude, rate of change, maximum differential pressure
and landing field elevation are displayed.
The system also includes the multi-function display, for viewing CMC
messages, and the Multi function Display ECS synoptic page to monitor the
outflow valve position.
AUTO PRESSURE CONTROL LOOP
The CPCS controller controls the cabin pressure by generating a speed
command for the outflow valve. The outflow valve maintains a safe cabin
pressure by modulating the rate at which the air flows out of the cabin.
The CPCS controller calculates a cabin reference from the ambient pressure
(PA) and inputs from the FMS.
The difference between the reference pressure (PC REF) and the actual
cabin pressure (PC ACT), named DELTA PC, produces a speed and
direction command for the motor interface. The motor interface directly
controls its associated motor of the outflow valve.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
CABIN PRESSURE CONTROL SYSTEM COMPONENTS
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 85
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
COMPONENTS
PRESSURIZATION CONTROL PANEL
The PRESSURIZATION control panel is installed on the right hand side of
the overhead panel in the cockpit. It has these switches:
 A rotary MODE selector switch
 A rotary spring-loaded LFE (Landing Field Elevation) switch
 A rotary spring-loaded CABIN ALT switch
 A guarded DUMP push-button switch
The MODE selector switch has three position:
 AUTO for automatic operation
 LFE CTRL for manual selection of LFE
 MAN for manual operation
When the MODE switch is set to AUTO, the CPCS operates fully
automatically without any crew attention during flight. The CPCS takes the
LFE value from the FMS.
The OUTFLOW switch is spring-loaded to the STOP position. When it is
turned to the UP position, the outflow valve is driven to the open position.
When it is turned to the DOWN position, the outflow valve is driven to the
closed position. The outflow valve is driven at a rate of 2 degrees per second.
The LFE switch is spring-loaded to the STOP position. When it is turned to
the UP position, the LFE is increased. When it is turned to the DOWN
position, the LFE is decreased. The LFE increases by 50 ft every 0.5 s.After
2 s, the LFE increases by 500 ft every 0.5 s.
The DUMP switch is used to depressurize the cabin in the event of
emergency evacuation, smoke evacuation or to rapidly equalize differential
pressure. The cabin is depressurized at a rate of 2000 SL ft/min. up to 12400
ft +/- 50 ft cabin altitude.
Positive Differential Pressure Limitation
When the MODE switch is set to LFE CTRL, the CPCS is still in automatic
operation, but the LFE values are selected manually via the LFE switch. The
LFE CTRL is used together with the LFE switch to select LFE. The LFE
ranges from -2000 ft to 14000 ft. When the MODE switch is set to MAN, the
CPCS operates in manual mode. The MAN switch is used together with the
CABIN ALT switch to manually control the position of outflow valve.
The CABIN ALT switch controls the position of the outflow valve in the
manual mode of operation. It only functions when the MODE selector switch
is set to MAN. It has these positions:
 UP
 DOWN
 STOP
ISSUE 1, 24 Sep 2014
Whenever the differential pressure exceeds the nominal differential pressure
by +4 hPa (+.06 PSID) the control logic will automatically open the outflow
valve to limit differential pressure (available only in AUTO mode).
An additional Independent control function will open the outflow valve if the
nominal differential pressure +20 hPa (+.29 PSID) is reached. This function is
available in both Auto and Manual modes.
A pneumatically actuated safety valve is also used to limit differential positive
pressure to +597 hPa (+8.66 PSID ).
FOR TRAINING PURPOSES ONLY
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
PRESSURIZATION CONTROL PANEL
ISSUE 1, 24 Sep 2014
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
CPCS CONTROLLER
The CPCS controller provides automatic cabin pressure control, failure
monitoring and recording and communication with other aircraft systems. The
CPCS controller has two separate, but identical, fully independent control
channels. Each control channel includes:
 Two cabin pressure sensors
 Cabin pressure control circuit
 BITE (Built-in Test Equipment) control circuit
 Motor driver circuit
 ARINC (Aeronautical Radio Incorporated) 429 I/O Interface
 Discrete I/O interface
 Serial Interface for software down load and shop interrogation
purposes
 EMI (ElectroMagnetic Interference) protection circuits on separate
board
 Non-volatile fault and flight data storage
The control channels communicate with each other via internal
communication buses. Each control channel is supplied by two separate
aircraft power supply sources for redundancy.
In automatic mode, only one control channel controls the outflow valve at any
time, the other is in hot stand-by. The CPCS controller switches active control
from one control channel to the other after each flight or when an auto failure
occurs. This gives the CPCS a dual redundant architecture.
The manual mode of operation overrides and bypasses the CPCS. The crew
controls the cabin pressure by manual control of the outflow valve. This gives
the CPCS a triple redundant architecture.
The CPCS provides positive pressure relief to avoid damage to the aircraft
due to positive over pressure.
When the differential pressure exceeds the maximum differential pressure of
597.08 hPa (8.66 psi), the CPCS software control logic opens the outflow
valve. This function is only available in the automatic mode of operation.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
CABIN PRESSURIZATION CONTROLLER
ISSUE 1, 24 Sep 2014
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
The CPCS controller provides automatic cabin pressure control. It also
performs BITE power-up, continuous and initiated tests. The CPCS controller
is installed in the forward avionics compartment. It has four built-in pressure
sensor ports, two for each control channel.
One sensor of the control channel is used for the control loop and indications,
the other is used as a backup for safety functions and indications. Four
electrical connectors, two on each end of the unit, provide interconnection to
other aircraft systems.
The independent control channels communicate via an internal CAN
(Controller Area Network) bus and internal discrete signals. Each control
channel is powered by two separate aircraft power supply sources for
redundancy.
In the operational state, if the control channel detects no faults and all BIT
functions are enabled, the pressure control is activated.
In the stand-by state, the control channel switches off drive power to the
outflow valve and some system performance monitoring tests are disabled. If
no faults are detected and manual mode is not selected, the pressure control
loop and the position control loop are held initialized to actual values. This
achieves a smooth transfer to the operational state in respect to cabin
pressure rates.
In the fail state, the control channel switches off drive power to the outflow
valve because faults have been detected. All outputs to other aircraft systems
are flagged invalid except ARINC information about the status of the system.
Channel one is powered by the 28 VDC (Volt Direct Current) essential buses
1 and 2. Channel two is powered by the 28 VDC essential buses 1 and 3.
The CPCS controller is part of a dual redundant system. It is active when the
system operates in the automatic mode. Only one control channel operates
the outflow valve at any given time. The other control channel is in hot
standby. Pressure sensor signals are transmitted via ARINC 429 to the
control circuits and are used for cabin pressure control logic. The control
channel calculates a reference value for cabin pressure from external aircraft
inputs and interna logic.The reference value is compared with the actual
cabin pressure and when a difference exists, an error signal is output. This
error signal is fed to one of the motors in the actuator to drive the outflow
valve to the desired position.
The initialization state performs these tasks:
 Power-up BIT (Built-in Test)
 Initialization of software
 Initialization of hardware
 Control channel determination for flight
 Resets all flight indications
 Initialization of pressure control loop
 Synchronisation to the other control channel
 Start normal control function
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
CPCS CONTROLLER
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 91
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
OUTFLOW VALVE
The outflow valve controls the air flow out of the aircraft fuselage. It is
installed on the forward fairing bulkhead.
The outflow valve consists of a valve body and a rotary actuator. The valve
body comprises a 8.5 in diameter butterfly valve, a two-piece butterfly valve
flap, a splined shaft and an actuator housing.
The valve body, valve flap and actuator housing are made of anodized
aluminium alloy. The valve flap is bolted around the splined shaft and moves
to the closed if loss of mechanical actuation occurs.
The rotary actuator consists of two brush less DC (Direct Current) motors, a
gear train and a dual channel potentiometer.
Each DC motor is controlled and monitored by a separate channel of the
CPCS controller. Only one DC motor drives the outflow valve at any time.
Both DC motors use the same actuator mechanism.
The gear train consists of two irreversible worm screws, a differential gear
stage and two stages of spur gears. The worm screws are linked directly to
the output shafts on the DC motors. The spiral angle of the worm screw
prevents back driving of the motors.
The dual potentiometer sends a position signal to each control channel of the
CPCS controller. This provides position feedback of the outflow valve in
automatic and manual modes of operation.
The CPCS has a fail-safe software logic to close the outflow valve if the cabin
pressure altitude reaches 14500 ft. This function overrides the normal
automatic operation only, it does not effect the manual operation of the
outflow valve.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
OUTFLOW VALVE
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
POSITIVE PRESSURE RELIEF VALVE
The positive pressure relief valve is a pneumatically actuated gate valve,
located on the rear pressure bulkhead, normally held in the closed position by
a pre-loaded spring.
Valve operation is independent of the Cabin Pressure Control System
controller. The relief valve provides both positive and negative pressure relief.
It contains a pilot valve that compares cabin pressure to ambient pressure.
If the pressure difference exceeds 8.66 psid, the pilot valve will open and the
differential pressure will act on the diaphragm to open the valve.
A micro switch is mounted on the valve to provide input to the Modular
Avionics Unit for status reporting. The static port connects the positive
pressure relief valve to ambient pressure.
The port is located at the rear fuselage section and has an integral heater
powered by 28 VDC to eliminate ice blockage.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
POSITIVE PRESSURE RELIEF VALVE
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
NEGATIVE PRESSURE RELIEF VALVE
Under normal flight conditions, the valve is in the closed position. The valve is
mechanically actuated using the self-balanced spring forces at the valve gate
and the ambient-to-cabin differential pressure. If the ambient pressure
exceeds the aircraft cabin pressure, the valve gate opens and limits the
negative pressure. The springs set the cap to open at a differential pressure
of -10 hPa (-0.15 psi). The valve is fully open at -35 hPa (-0.51 psi).
The safety valve has also a negative relief function. If the ambient pressure
acting on the underside of the gate valve exceeds the cabin pressure, the
gate valve opens allowing air from ambient to flow into the cabin.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
NEGATIVE PRESSURE RELIEF
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
OPERATION
CABIN PRESSURE CONTROL MODES
During ground and flight operation the CPCS determines the current flight
mode depending on ARINC information. The system operates with the
following flight modes:
 Ground (GN)
 Takeoff (TO)
 Climb (CI, CE)
 Cruise (CR)
 Descent (DI)
 Abort (AB)
The mode logic uses the following information from the MAU (Modular
Avionics Unit) to determine the current flight mode:
 Landing gear status and validity (generated by FADEC (Full- Authority
Digital Engine-Control)
 Engine takeoff power status and validity (generated by FADEC)
 Ambient pressure (generated by ADC)
 Cruise Flight Level (CRFL) and validity (generated by FMS) The flight
mode transitions for a normal flight are as follows:
 Ground Mode - The ground mode is active when the landing gear
status shows that the landing gears are compressed and the engines
takeoff power signals are not set.
 Ground to Taxi Mode - The taxi mode becomes active as soon as the
doors signal indicates the doors are closed and both engines rotation
(N2) are higher than 60%. This mode is only possible to be activated
from the ground mode.
 Climb Mode to Abort - If the aircraft stops climbing and begins an
immediate descent, the CPCS interprets this as a flight abortion.
 The abort is only possible if the cruise mode has not been entered
and either the aircraft is below 10000 ft absolute or is less than 5000
ft above the takeoff field.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
GROUND AND TAKEOFF MODES
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
CLIMB AND CRUISE MODES
 Climb external is used when a valid CRFL is received from the FMS.
 Climb internal is used if the CRFL is invalid or the FMS fails.
 Climb Mode to Abort - If the aircraft stops climbing and begins an
immediate descent, the CPCS interprets this as a flight abort. The
abort is only possible if the cruise mode has not been entered and
either the aircraft is below 10000 ft absolute or is less than 5000 ft
above takeoff field.
 Climb Mode to Cruise - In the climb external mode, the mode logic
switches from climb to cruise when the aircraft reaches the planned
CRFL. In the climb internal mode, the mode logic switches from climb
to cruise when the aircraft stops climbing.
 Cruise Mode to Descent - The descent mode becomes active when
the aircraft starts descending after the cruise.
 Descent to Ground - The ground mode is active when the landing
gear status indicates that the aircraft is on the ground.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
CLIMB AND CRUISE MODES
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
DESCENT AND ABORT MODES
The CPCS will transition to DESCENT mode by selecting the landing field
altitude before the aircraft leaves the cruise flight level. The target pressure
will be set to landing field altitude plus 0.12 psi to ensure landing with the
CPCS in control. Cabin rate of change depends on cabin pressure, landing
field pressure and ambient pressure within 200 and 750 fpm.
If the aircraft stops climbing and begins immediate descent, the CPCS
transits to ABORT mode. This transition is only possible from climb mode
when the aircraft altitude is below 10000 ft absolute or 5000 above the
takeoff field. In this mode, cabin pressure will be scheduled back to the takeoff altitude, with a 5000 fpm rate of change.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
DESCENT AND ABORT MODES
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
MANUAL MODE
The manual mode of operation gives the flight crew manual control of the
cabin pressure.
When the MODE selector switch on the pressurization control panel is in the
MAN position, it configures the CPCS for manual operation. Both automatic
channels revert to the stand-by state. The manual operation is performed by
one control channel which is selected automatically. The crew has direct
manual control of the outflow valve via the CABIN ALT switch on the
pressurization control panel.
The CPCS detects any failure in the manual mode and provides fault
messages to the EICAS and CMC (Central Maintenance Computer).
The EICAS shows the message “PRESN MAN FAIL” if the manual function of
both channels has failed.
Failures detected during flight which do not require crew action are displayed
on the CMCM (Central Maintenance Computer Module) after landing.
Manual mode is differential pressure limited but is not cabin altitude limited.
In manual mode there is no automatic cabin depressurization on ground
(after landing).
When in manual mode, the crew shall depressurize the cabin to a maximum
differential pressure of 0.2 psid, before landing.
After landing the crew shall open the OFV fully.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
MANUAL MODE
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FOR TRAINING PURPOSES ONLY
Page: 105
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
ABNORMAL OPERATION
These fault protection schemes are used to prevent the aircraft
depressurization or overpressurization:
 Cabin altitude limit in automatic mode
 Differential pressure control
 Auto fault indication
 Manual fault indication
 Maintenance required indication
 Excessive cabin altitude warning
Two pressure sensors measure the cabin pressure in each control channel. If
the cabin altitude exceeds the limit of 14500 ft ±500 ft, logic circuits close the
outflow valve automatically. This is done independently from the pressure
control logic.
If the CPCS BIT logic detects a failure within a CPCS component, a CMC
message is generated for later maintenance action. This is for components
that are not essentially required to finish the actual flight but require
maintenance action.
Both automatic control channels provide a high cabin altitude warning at
10000 ft cabin altitude independent of the selected mode.
In automatic mode, if the aircraft operation requires a cabin landing field
elevation above 10000 ft, the CPCS controller inhibits the 10000 ft warning
up to a 14000 ft landing field elevation. The 10000 ft warning is always active
for a cabin altitude of 14000 ft or higher.
An additional circuit limits the cabin altitude to 12700 ft ±300 ft. This limitation
is not available in manual mode.
When the differential pressure exceeds the maximum differential pressure of
592.94 hPa (8.60 psi), the control logic opens the outflow valve to limit
differential pressure. An additional independent control function opens the
outflow valve if a nominal differential pressure of +24 hPa (0.34 psi) is
reached. If the control channel logic detects a major failure of one of the auto
control channels, an EICAS message is generated to alert the crew that the
redundancy was lost. With the loss of the auto control channel redundancy,
the maximum duration is limited as stated in the MEL (Minimum Equipment
List). If both auto control channels are detected faulty, the EICAS indication
changes color to alert the crew.
The crew must select the manual mode of operation.
If the BITE logic of the channels detect a major failure of both of the manual
functions, an indication is displayed on the EICAS. The crew must descend
the aircraft to 10000 ft because of loss of the CPCS function.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
ABNORMAL OPERATION
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 107
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
INDICATIONS
In case of a Cabin Pressure System fault, EICAS messages are displayed:
 If one controller channel fails, the EICAS advisory message PRESN
AUTO FAULT will be displayed
 If both controller channels fail, the EICAS caution message PRESN
AUTO FAIL will be shown
 When both channels are unable to operate in manual mode, the
caution message PRESN MAN FAIL will be displayed
 If cabin altitude exceeds 9700 ft, a warning message HI CABIN ALT
will illuminate, and an aural warning, CABIN, will sound.
The EICAS Display also provides a continuous status of cabin altitude, cabin
rate, differential pressure, and landing field elevation.
Display color indicates current status of displayed value.
Green - Normal range
Amber - Advisory range
Red – Warning
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
EICAS INDICATIONS
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
Each control channel of the CPCS controller has redundant ARINC
transmitters to MAU 1 and MAU 2 to provide indications to the EICAS.
This information is shown continuously on the main page of the EICAS
display.
The EICAS indications are:
–ALT– Cabin altitude: Indicates the cabin altitude in feet. The color of the
indication changes as the altitude changes as follows (Resolution: 100 ft):
For airfield altitude < 9400 ft:
 Green for values £ 8100 ft
 Amber for values > 8100 ft and £9,700 ft.
 Red for values > 9700 ft.
 Amber dashes for invalid data.
For airfield altitude ≥ 9400 ft:
 Green for values < airfield altitude +500 ft.
 Red for values ≥ airfield altitude +500 ft.
 Amber dashes for invalid data.
–RATE– Cabin Pressure Rate: Indicates cabin pressure rate in feet per
minute at sea level ( SLft/min). The color of the indication changes as the
cabin pressure rate changes as follows (Resolution: 50 SLft/min):
 Amber for values above +2,500 SLft/min.
 Green for values -2,500 to +2,500 SLft/min.
 Amber for values below -2,500 SLft/min.
 Amber dashes for invalid data.
–Delta P– Cabin differential pressure: Indicates cabin differential pressure in
psi. The color of the indication changes as the D P changes as follows
(Resolution: 0.1 psi):
 Green for values -0.2 to +8.4 psi.
 Amber for values -0.5 to -0.3 psi.
 Amber for values +8.4 to +9.1 psi.
 Red for values below -0.5 psi.
 Red for values above +9.1 psi.
 Amber dashes for invalid data.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
EICAS INDICATIONS (CONTINUED)
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
LFE– Landing Field Elevation
TRAINING INFORMATION POINTS
Indicates landing field elevation in ft. The color of the indication changes as
the LFE value changes as follows (Resolution: 100 ft):
 Green for FMS values.
 Cyan for manual input with “CTRL” in front of value.
 Amber dashes for invalid data.
 Green dashes when manual mode is active.
Warning: TO PREVENT ELECTRICAL SHOCK OR DAMAGE,
DISCONNECT ALL SOURCES OF ELECTRICAL POWER
BEFORE YOU INSTALL OR REMOVE THE PRESSURIZATION
CONTROLLER. MAKE SURE THAT A PERSON APPROVED TO
USE
MODERN
METHODS
OF
FIRST
AID
AND
RESUSCITATION IS ALWAYS NEAR YOU.
Caution:
THE MODULE OR UNIT CONTAINS ELECTROSTATIC
DISCHARGE SENSITIVE (ESDS) ITEMS. OBEY THE
APPROVED INDUSTRY PRECAUTIONS WHEN YOU TOUCH,
REMOVE, OR INSERT PARTS OR ASSEMBLIES. DAMAGE
CAN OCCUR FROM ELECTROSTATIC DISCHARGE.
The CPCS controller has BIT (Built-in Test) logic circuits to detect failures
within each control channel or in CPCS functions. All detected faults are
stored in NVM (Non-Volatile Memory) and are continuously transmitted to the
EICAS and CMCM (Central Maintenance Computer Module) on the ARINC
(Aeronautical Radio Incorporated) 429 output bus.
The CPCS is provided with BITE that provides failure indications to the
EICAS display and the CMC.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
EICAS INDICATIONS (CONTINUED)
ISSUE 1, 24 Sep 2014
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Page: 113
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
DIAGNOSTIC AND TEST
The CPCS controller has BIT logic to detect failures within each control
channel or in the CPCS functions. If the BIT logic detects a fault in the active
control channel, the control channel goes into automatic fail. The CPCS
switches automatically to the other control channel without any workload to
the crew. A channel Fail message is displayed on the CMC display.
All detected faults are stored in NVM (Non-Volatile Memory) and can be
down loaded for maintenance purposes off-wing. All faults are continuously
transmitted to EICAS and CMCM via the ARINC 429 output bus.
The CPCS checks internal parameters and functionality. The internal fault
detection logic detects and isolates single LRU (Line Replaceable Unit) and
interconnection failures that cause loss of functionality or redundancy.
The CPCS performs these tests:
 Power-up test
 Continuous hardware and software tests
 Continuous function tests
The power-up test is done after a cold start, a reset or a power supply
interrupt. During the power-up test internal devices initialize and check the
hardware and software of the CPCS. When the test has passed, the main
page is shown on the EICAS display. When the power-up test fail, the PRSN
AUTO FAULT message is displayed on the EICAS.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
BUILT-IN TEST
ISSUE 1, 24 Sep 2014
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
ATA 21-50 COOLING
INTRODUCTION
The air conditioning system utilizes two identical cooling packs that provide
condition bleed air for cabin heating and cooling.
The packs provide condition bleed air for cabin heating and cooling, and
include the following components:
 Dual heat exchanger,
 Air cycle machine,
 Condenser-reheater,
 Water collector,
 Add heat bypass valve and
 temperature sensors.
There are also two external components:
 The Pack bypass valve, and a
 Pack flow control valve which together control pack operation.
During normal operation, each cooling pack provides half of the total fresh
airflow; however, a single pack is capable of providing 67% of the total flow
and ensuring safe aircraft ventilation and temperature control capability.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
AIR CONDITIONING SYSTEM
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
DESCRIPTION
The air conditioning system utilizes two identical air cooling packs, right and
left, to condition bleed air for cabin heating and cooling. Each air cooling pack
consists of a dual heat exchanger, air cycle machine, condenser/reheater,
water collector, valves and temperature sensors. The primary function of the
air cooling pack is to supply conditioned air to the cabin distribution system
for environmental control. The air cooling pack also contains an internal
condensing water collection system which removes moisture from the cooling
pack air flow. Hot air from the engine bleed system is precooled in the dual
heat exchanger using cold ram (outside) air to remove the heat. An air cycle
machine within the pack contains two cooling turbines which generate cold
air, through expansion, for cooling cabin.
An equal quantity of filtered re circulated air is mixed with air from the air
conditioning packs. The high quantity of supply air results in a complete cabin
air exchange about every 2.5 to 3.5 minutes (based on aircraft configuration
and altitude), or about 18 to 25 times an hour.
The high air exchange rate is necessary to control temperature gradients,
prevent stagnant cold areas, and maintain air quality.
The cooling pack system conditions hot bleed air for cabin air conditioning.
There are two identical cooling packs (right and left) per aircraft and they are
located in the ECS (Environmental Control System) pack bay in the forward
fairing of the aircraft.
The cooling pack is an air cycle refrigeration system that uses air passing
through and into the airplane as the refrigerant. The cooling pack system
automatically controls the temperature and decreases the humidity of the
cockpit and cabin air. The two cooling packs, which are installed in the
forward part of the wing-to-fuselage fairing, provide dry, sterile, and dust free,
conditioned air to the flight deck and passenger cabin at the proper
temperature, flow rate, and pressure to satisfy pressurization and
temperature control requirements.
An equal quantity of filtered, re circulated air is mixed with air from the cooling
packs.
A flow control valve regulates flow of bleed air into the air conditioning packs.
The refrigeration pack is out fitted with sensors and valves for temperature
and operational control, and heat exchangers that use outside ram air for
excess heat dissipation.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
ECS PACK
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
FLOW CONTROL
The flow of air to the air conditioning packs is measured using a differential
pressure sensor which is mounted on a venturi duct. The differential pressure
sensor sends an electronic signal to the AMS controller. The AMS controller
uses the differential pressure, bleed manifold pressure, and pack inlet
temperature to calculate the airflow that goes to the air conditioning pack.
The AMS controller then supplies a torque motor current command to
modulate the pack flow control valve to obtain the desired pack airflow rate.
The pack flow control also is based on engine bleed availability. During
normal operation each pack flow control valve is controlled to accepted half
of the total flow reference. During dual engine bleed or single engine bleed
and single pack operation, the total fresh air shall be reduced to 67% of the
total flow reference. During single engine bleed and dual pack operation, the
total fresh air flow shall be reduced to 75% of the total flow reference.
Note:
During single engine bleed operation the opposite side air
conditioning pack will be turned off if a slat anti- ice operation is
required.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
FLOW CONTROL
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
COMPONENTS
PACK FLOW CONTROL VALVES
VENTURI DELTA-P SENSORS
There are two pack flow control valves, right and left, located upstream of the
left and right air cooling packs.
The differential pressure sensor is mounted on the flow sensing venturi duct
directly upstream of the pack flow control valve. The sensor provides a 0 to
10 VDC (Volt Direct Current) electronic signal to the AMS controller, which is
used to calculate the air flow that goes into the environmental control system.
The sensor is hermetically sealed and consists of two input pressure ports,
and internal pressure transducer, and an electrical connector. There are two
differential pressure sensors per aircraft (one per cooling pack).
The pack flow control valves are modulated by the AMS (Air Management
System) controller to obtain the desired cabin ventilation rates.
The pack flow control valve is a pneumatically actuated butterfly valve
controlled by a torque motor.
Modulation of the valve is electronically controlled by the AMS controller. The
AMS controller applies a 0 to 50 mA torque motor current to position the
valve as necessary to obtain the proper cabin ventilation rates.
The valve incorporates a closed position switch which is used to provide
position feedback to the AMS controller.
A removable air filter is used to filter airborne contaminants from the supply
air.
A locking screw installed in the actuator housing can be used to lock the
valve closed.
FLOW SENSING VENTURIS
The flow sensing venturi duct is a tapered steel duct that is used to calculate
the air that goes into the air conditioning system. The taper in the venturi duct
creates an orifice. The venturi duct contains pressure sensing ports on the
upstream and downstream sides of the duct orifice. Airflow across this duct
orifice is measured by a differential pressure sensor which is mounted on the
venturi duct. This differential pressure is used by the AMS controller to
calculate the air flow.
There are two venturi ducts per aircraft (one per cooling pack).
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
FLOW CONTROL VALVE
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Page: 123
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
DUAL HEAT EXCHANGERS
The dual heat exchanger and fan inlet diffuser housing assembly is
assembled in each of the ECS packs of the integrated air management
system. In the pack, bleed air flows through the primary circuit of the dual
heat exchanger to remove heat before entering the compressor section of the
air cycle machine. The flow then passes through the secondary circuit of the
heat exchanger before continuing on to the reheater. Both bleed circuits of
the heat exchanger are cooled by ram air in series through the secondary
first, then through the primary core sections. After exiting the primary core,
the ram airflow enters the outer housing of the fan inlet diffuser housing
where it is either pulled through the fan, or passes through the fan bypass
check valve where it is vented to the ram overboard ducting.
The dual heat exchanger is an aluminum design, which consists of sheet
metal or cast headers and mount pads fusion-welded to a plate-fin core. The
primary section is a single-pass, cross-flow configuration. The secondary
section is a two-pass cross-counterflow configuration. The dual heat
exchanger/fan inlet diffuser housing contains two access windows which can
be used for inspection and or cleaning of the heat exchanger ram air circuit.
The fan inlet diffuser housing is welded to the ram outlet header of the dual
heat exchanger.
FAN BYPASS CHECK VALVE
The fan bypass check valve is a 12 in diameter hinged, petal-type check
valve which has six petals that cover six orifice windows in a single valve
seat. The valve allows airflow through the orifice windows in one direction.
Flow in the opposite direction (reverse flow) is prevented by the petals
closing on the aluminium check valve frame.
The fan bypass check valve is installed in the cooling pack between the fan
inlet diffuser housing and the ram air outlet duct, and allows ram air to bypass
the air cycle machine fan whenever pressure in the ram air circuit exceeds
the ACM fan outlet pressure. This fan bypass function is necessary to
prevent ACM damage caused by excessive fan surge margins. There are two
fan bypass check valves per aircraft (one per cooling pack).
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FOR TRAINING PURPOSES ONLY
Page: 124
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
DUAL HEAT EXCHANGER
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Page: 125
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
AIR CYCLE MACHINE
The air cycle machine provides the source for pack cooling. The external
structure consists of a fan and compressor housing, a first stage turbine
housing, and a second stage turbine housing. Each housing is made of cast
aluminium.
The ACM internal structure has two turbine rotors which drive a compressor
rotor and a cooling fan rotor.
The four rotors and two shaft segments turn as one assembly locked together
by a tie rod.
The assembly rotates in a pair of hydrodynamic, foil-type journal bearings.
Axial movement is limited by a pair of hydrodynamic thrust bearings. These
hydrodynamic foil-type bearings use no oil and require no scheduled
maintenance.
The fan rotor is attached to one end of the assembly and is positioned
adjacent to the fan shaft segment followed by the compressor rotor, first
turbine rotor, turbine shaft segment, and second turbine rotor. The turbine
shaft segment includes both a journal bearing surface and the thrust disk on
which the two bearings act.
A tie-rod goes through the centre of the shaft and rotor segments and holds
the assembly together axially. The tie-rod is assembled with a high preload
which permits all components of the assembly to operate as a one shaft
system.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
AIR CYCLE MACHINE COMPONENTS
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Page: 127
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
CONDENSER/REHEATER
WATER SPRAY NOZZLE
The condenser/re-heater is an aluminum dual-heat exchanger consisting of
headers and mounts welded to a core. Both core sections are single pass,
crossflow, plate-and-fin designs. The condenser cold circuit is situated
between the two turbine stages of the air cycle machine and is never
subjected to sub-freezing air temperatures; therefore, it does not require
complicated features for the prevention of ice buildup, which other systems
using the conventional chilled recirculation cycle demand.
The water spray nozzle is mounted in the ram air inlet ducting directly
upstream of the dual heat exchanger. Water, which is collected in the water
collector, is routed through drain line to the water spray nozzle. The water
spray nozzle sprays the water on the ram inlet face of the secondary heat
exchanger. This cools the air that goes into the secondary heat exchanger
and improves heat exchanger performance.
The condenser/reheater core consists of alternating hot and cold fin layers. A
cast manifold is welded to the coreís hot inlet. The manifold provides most of
the inter-pack flow passages between the heat exchangers, water collector,
and ACM. The manifold bolts to a base on the dual heat exchanger end
sheet and seals to the primary and secondary circuits using face seals.
WATER COLLECTOR
The water collector is a brazed and welded assembly. The collector body is
constructed of two aluminium-brazed sub assemblies welded together at the
outside diameter. Each section of the sub assembly is made of spun and
hydro-formed sheet metal parts.
The water collector removes water from the condenser/reheater heat
exchanger and sends the dry air to the air cycle machine. A swirl vane at the
water collector inlet sends the water to the duct walls. A clearance between
the diffuser section and the air return diffuser section catches most of the
water from the airflow. A drain boss located at the lowest section of the
collector lets water drain by gravity and air pressure. An overflow drain boss
located slightly above the lowest point lets water drain if the primary port is
clogged.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
CONDENSER
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Page: 129
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
PACK BYPASS VALVE
There are two pack bypass valves, a right and a left, used in the air cooling
pack system. The pack bypass valve modulates to maintain a desired pack
outlet temperature. The pack bypass valve is a pneumatically actuated
butterfly valve controlled by a torque motor. Modulation of the valve is
controlled electronically by the AMS controller. The AMS controller applies a
0 to 50 mA torque motor current to position the valve as necessary to obtain
the proper cooling pack outlet temperatures. The valve contains a removable
air filter which is used to filter airborne contaminants from the supply air. A
locking screw installed in the actuator housing can be used to lock the valve
closed.
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Page: 130
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
BYPASS VALVE
ISSUE 1, 24 Sep 2014
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Page: 131
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
ADD HEAT, AND LOW LIMIT BYPASS VALVE
ADD HEAT VALVE
Bleed air passing by the pack inlet temperature sensor and through the
primary heat exchanger enters the air cycle machine compressor.
The add heat valve is a 1 in diameter pilot operated shutoff valve which is
used to control temperatures at the condenser inlet and outlet locations within
the air conditioning pack. The valve is closed by applying 15 VDC to pins A
and B. There are two add heat valves per aircraft (one per cooling pack).
Maintenance of the valve is on condition.
Compressor inlet and outlet temperature is sensed by temperature sensors
and forwarded to the AMS controller.
The main flow from the compressor goes through the secondary heat
exchanger and on to the condenser/reheater. Some hot air is tapped and
directed to the Add Heat Valve to maintain turbine second stage inlet
temperature.
Air from the condenser/reheater is directed to the first stage turbine, where
the temperature will drop.
The Low Limit Bypass Valve is installed parallel to the first stage turbine. The
valve provides additional warm air to maintain condenser inlet temperature.
Air flows through the condenser and enters the second stage turbine for a
further temperature reduction.
Turbine outlet cold air is mixed with pack bypass air to achieve the requested
duct temperature.
LOW LIMIT VALVE
The low temperature limit bypass valve is an electrically actuated valve,
which is installed integral to the air cycle machine turbine housing. The linear
actuator will be used to position a piston in a valve housing, which meters the
amount of warm air bypass flow to control the temperature in the condenser
inlet duct. The feedback for positioning is the downstream duct temperature.
The actuator operates to position the valve in response to electrical signals
from the AMS electronic controller. The control logic will be based on
ìbump/ stop/checkî, where a signal is sent to the actuator to extend or
retract in steps.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
LOW LIMIT BYPASS VALVE, ADD HEAT VALVE AND ECS PACK BYPASS VALVE
ISSUE 1, 24 Sep 2014
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Page: 133
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
TEMPERATURE SENSORS
The air conditioning pack temperature control has five temperature sensors,
which supply data to the AMS controller.
The sensors are:
 Pack inlet temperature sensor,
 Compressor inlet temperature sensor,
 Compressor outlet temperature sensor,
 Condenser inlet temperature sensor and
 Pack outlet temperature sensor.
All of these sensors are dual element sensors (except the pack inlet
temperature sensor, which has a single element) in order to improve system
reliability. The AMS controller monitors all sensor voltages in order to control
pack operation or determine pack failure.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
TEMPERATURE SENSORS
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Page: 135
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
OPERATION
Air is cooled in the primary section of the dual heat exchanger using ram air
to remove the heat. The air is then compressed by the compressor portion of
the dual turbine ACM. The heat generated by compression is removed by the
secondary portion of the dual heat exchanger, using ram air. The air is then
passed through the condenser/reheater where it is sub-cooled within the
condenser using the cold exhaust air from the first stage turbine. This cooling
process condenses water from the air to permit it to be collected by the water
collector. The collected water is moved to the spray nozzle, which is located
in the secondary ram inlet header of the dual heat exchanger.
Pack outlet temperatures are continuously monitored by the AMS controller
using electronic feedback from the pack outlet temperature sensor. The pack
outlet temperature is controlled by adding hot pack inlet air to the pack outlet
airflow. This is accomplished by modulation of the pack bypass valves. The
AMS controller reads actual pack outlet temperatures and sends a torque
motor current command to modulate the pack bypass valves to obtain the
desired pack outlet temperatures.
The water is sprayed on the ram air face of the core to increase the heat
exchanger performance through evaporative cooling. After exiting the water
collector, the air flows through the re-heater portion where it is preheated to
increase first stage turbine performance.
After expansion through the first stage turbine portion of the ACM, the air
passes through the cold side condenser portion of the condenser/ reheater
where it removes the heat for condensation. After exiting the cold side of the
condenser, the air enters the second stage turbine of the ACM where it is
expanded to provide the cold air source for cabin cooling.
The condenser inlet temperature is continuously monitored by the AMS
controller using electronic feedback from the condenser inlet temperature
sensor. The condenser inlet temperature is controlled by adding warm
compressor outlet air to the condenser inlet airflow. This is achieved by
modulation of the low limit valve and/or the opening and closing of the add
heat valve. The condenser inlet temperature is controlled to 34 ∞F/1.1∞C
under most pack operating conditions to prevent water from freezing in the
condenser. In certain low humidity conditions the condenser inlet may be
controlled to 50 ∞F/ 10 ∞C.
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FOR TRAINING PURPOSES ONLY
Page: 136
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
AIR CYCLE MACHINE OPERATION
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 137
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
ECS OFF REQUEST
The FADEC may send an ECS OFF signal to the AMS controller, requesting
that no bleed air be extracted from the engine for the air- conditioning
system. The FADEC sets this signal depending on the TDS input (REF ECS
OFF), pressure altitude, flight phase and engine failure detection.
If the ECS is bleeding air from the engine and the FADEC ECS OFF request
is true and Altitude is below 15 000 ft, both ECS packs will be commanded
OFF. The ECS cooling packs will be shut down at -30 ppm/ sec after
receiving the ECS OFF signal from the FADEC. The APU can be used as a
valid bleed air source when the ECS OFF signal is set to true and Anti-ice is
not required.
In response to the ECS OFF signal the AMS controller has the following
requirements:
If the FADEC transitions the ECS OFF signal from true to false, the both ECS
cooling pack FCV’s will be automatically opened without any pilot action. The
AMS will disregard the FADEC ECS OFF signal if aircraft altitude is above
15,000 ft.
In general, the AMS controller will use the ECS OFF signal from the incontrol FADEC channel. If the AMS controller loses communication from one
SPDA then AMS controller will use the other SPDA as a backup source of
information for the ECS OFF and channel in control signals.
The time from the ECS OFF signal being received in the AMS controller to
ECS cooling pack FCV’s closing will be less than 5 seconds when
commanded ON again by the AMS controller.
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FOR TRAINING PURPOSES ONLY
Page: 138
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
ECS OFF LOGIC
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 139
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
PACK RELATED MESSAGES
TRAINING INFORMATION POINTS
The Pack-related EICAS messages are:
 PACK FAIL CAUTION if any pack component develops a fault,
 PACK OFF advisory message if the pack is switched off, or
 PACK LEAK caution message when an overheat is detected in the
pack high pressure bleed duct.
To prevent electrical shock or damage, disconnect all electrical power
including compressor inlet and discharge temperature sensors, condenser
inlet temperature sensors, and pack inlet and outlet temperature sensors
before installation or removal of the cooling pack.
CMC messages will be provided to determine failed pack components if the
PACK FAIL message is present.
The pack will be disabled in the following conditions:
 bleed source not available,
 pack switch is OFF,
 left or right engine start with weight on wheels,
 duct leak or
 if the AMS built-in-test detects failure.
Warning: DO NOT TOUCH THE COOLING PACK SYSTEM DUCTS OR
COMPONENTS IMMEDIATELY AFTER THE SYSTEM IS
TURNED OFF. THE HIGH AIR TEMPERATURE CAN CAUSE
INJURY TO YOU.
Caution:
BE CAREFUL WHEN YOU HANDLE THE PACKS, VALVES,
SENSING ELEMENTS, AND AIR CONDITIONING DUCTS. DO
NOT LET OIL, GREASE OR RESIN GET ON THESE
COMPONENTS.
There must be no twists or bends on the bellows. In addition to that, the ducts
and bellows must be aligned with the adjacent components. This is to avoid
damage to the ducts installation and to the air conditioning packs during
operation. There must be no twist or asymmetrical deformation of the rubber
mounts. This is to avoid overloading of the air conditioning pack installation
and prevent an eventual failure of the air cycle machine.
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 140
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
PACK RELATED MESSAGES
ISSUE 1, 24 Sep 2014
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Page: 141
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
DIAGNOSTIC AND TEST
ADD HEAT VALVE IBIT
During the IBIT, preconditions are:
 WONW
 Airspeed below 50knots
 Channel in control and
 PACK ON
 Condenser temperature below 10deg C
Test will drive the valve open, consequence: heat will be added to T1 turbine
inlet. Test will check for temperature rise.
CONDENSER IBIT
During the IBIT , preconditions are:
 WONW
 Airspeed below 50knots
 Channel in control and
 PACK ON
 Source APU
 Manifold pressure above 12psi
Test will drive flow control valve fully OPEN and bypass valve fully CLOSED.
This will create full flow through the air cycle machine, checking condenser
operation will maximum airflow.
LOW LIMIT BY-PASS VALVE IBIT
During the IBIT , preconditions are:
 WONW
 Airspeed below 50knots
 Channel in control and
 PACK OFF
The test will drive the valve open and closed for 60 seconds
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FOR TRAINING PURPOSES ONLY
Page: 142
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
PACK TESTS
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FOR TRAINING PURPOSES ONLY
Page: 143
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
ATA 21-60 TEMPERATURE CONTROL
INTRODUCTION
The temperature control system provides closed loop control for the flight
deck and passenger cabin. The cabin two-zone configuration is an aircraftselectable option.
The flight deck and passenger cabin temperatures are electronically
controlled by the AMS controller between 19∞C and 30∞C. The AMS
controller compares the actual temperature provided by the temperature
sensors to the selected temperature. If a difference exists, the AMS controller
will adjust the target duct temperature by modulating the pack bypass valve
position until the selected temperature is achieved. In case of ambient sensor
failure, the system defaults to the duct temperature sensor, and if the selector
fails, the system defaults to a 75∞F/ 24∞C zone temperature.
ZONE TEMPERATURE CONTROL
Cabin Zone Temperature Sensor locations.
 Cabin Zone Temperature Sensor also uses ejector to draw ambient
air across sensor element.
 Ambient air is drawn from space between overhead bins.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
AMS TEMPERATURE CONTROLLER
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 145
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
DESCRIPTION
COCKPIT ZONE CONTROL
The temperature control system provides independent temperature control
for the cockpit zone. During normal operation the cockpit zone receives
airflow from the left air conditioning pack and the left recirculation fan.
The cockpit zone temperature is electronically controlled by the AMS (Air
Management System) controller. The AMS controller interfaces with a cockpit
temperature selector (potentiometer) to determine the desired cockpit
temperature.
The AMS controller compares the selected cockpit temperature to the actual
cockpit zone temperature. The difference between the selected temperature
and the actual cockpit temperature is used to calculate a target cockpit zone
duct temperature. The AMS controller will then modulate the left pack bypass
valve to meet the target cockpit zone duct temperature.
The cockpit temperature control system contains two identical electronic
sensors which provide temperature feedback to the AMS controller. One
sensor is located in the cockpit zone and the other sensor is located in the
cockpit duct, downstream the mixing duct.
The cockpit temperature is selected by the flight crew using the CKPT
selector.
During normal operation, the cockpit zone receives airflow from the left air
conditioning pack and the left recirculation fan. Under normal operating
conditions, the cockpit temperature is controlled by modulation of the left
pack bypass valve. Hot pack bypass air is mixed with cold pack discharge air
to obtain the desired zone temperature.
Two temperature sensors each located in the cockpit zone and in the cockpit
duct provide electronic signals to the AMS controller. Each temperature
sensor contains two independent sensing elements which provide electronic
signals to channel 1 and channel 2 of the AMS controller. This provides for
redundancy so that failure of an individual sensing element will have no effect
on cockpit temperature control.
Using feedback from the temperature selector and the temperature sensors
the AMS controller will then change the left air conditioning pack outlet
temperature to achieve the desired cockpit zone temperature.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
COCKPIT ZONE CONTROL
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Page: 147
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
PASSENGER CABIN SINGLE-ZONE CONFIGURATION
The passenger cabin receives air from the left and right air conditioning
packs, routed through the mixer duct, where it is blended with re circulated air
from the fans. Air is then routed to the front and aft passenger cabin
distribution ducts. In the single cabin zone configuration, the passenger cabin
temperature is controlled by changing the right air conditioning pack outlet
temperature.
The single configuration includes two dual sensors, one ambient temperature
sensor located in a Duct by the overhead bins, and the other cabin duct
temperature sensor downstream of the mixer.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
SINGLE CABIN ZONE CONFIGURATION
ISSUE 1, 24 Sep 2014
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
TWO-ZONE CONFIGURATION
The two cabin zone configuration uses a separate trim system for
independent control of forward and aft cabin zones.
Hot air is tapped from the right air conditioning pack for zone temperature
control.
The system includes:
 two trim modulating valves,
 two ejectors and
 three dual temperature sensors.
The AMS controller compares the selected zone temperatures to actual zone
temperatures. The difference between the selected temperature and the
actual zone temperature is used to calculate a target duct temperature for
both the forward and aft cabin zone ducts. The AMS controller will then
modulate the right pack bypass valve, via the torque motor command, to
meet the coldest cabin duct target temperature.
The AMS controller compares the selected zone temperatures to actual zone
temperatures. The difference between the selected temperature and the
actual zone temperature is used to calculate a target duct temperature for
both the forward and aft cabin zone ducts. The AMS controller will then
modulate the right pack bypass valve, via the torque motor command, to
meet the coldest cabin duct target temperature. The trim bypass valve for the
coldest zone will be sent a signal to close. The AMS controller will then
modulate the opposite zone trim modulating valve to meet the warmest cabin
duct target temperature.
The trim air system utilizes two trim air modulating valves, two hot air
ejectors, and associated ducting to independently control the air temperature
entering the forward and aft passenger cabin distribution ducts. This is
accomplished by mixing hot air from the ejectors directly into the forward and
aft distribution duct openings within the mixing duct. The amount of hot air
flowing to the ejectors is controlled electronically by the AMS controller
through modulation of two trim air modulating valves.
The passenger cabin temperature is selected by the flight crew using the
PAX CABIN selector. The forward and aft passenger cabin zone
temperatures can be selected by the flight attendant using CABIN
TEMPERATURE selectors located on the attendant control panels.
The passenger cabin zone requiring the coldest air is controlled by
modulation of the right pack bypass valve. The opposite zone (warmest zone)
temperature is controlled by modulation of the trim air modulating valve
related to that zone.
Temperature sensors located in the forward and aft cabin zone and in the
forward and aft cabin ducts provide actual temperature via electronic signals
to the AMS controller.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
TWO CABIN ZONE CONFIGURATION
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
COMPONENTS
TRIM MODULATING VALVES
The zone trim valves regulate hot bleed flow to the trim ejectors, which are
installed in the mixer duct.
The valves are electronically controlled and pneumatically operated butterfly
valves.
The valves are fail-safe closed and can be manually locked in the closed
position. The trim ejectors directionally inject hot bleed air into the forward
and aft cabin outlet ducts.
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
TRIM MODULATING VALVES
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Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
OPERATION
During normal operation, the cockpit zone receives airflow from the left air
conditioning pack and the left recirculation fan. Under normal operating
conditions, the cockpit temperature is controlled by modulation of the left
pack bypass valve. Hot pack bypass air is mixed with cold pack discharge air
to obtain the desired zone temperature.
Two temperature sensors each located in the cockpit zone and in the cockpit
duct provide electronic signals to the AMS controller. Each temperature
sensor contains two independent sensing elements which provide electronic
signals to channel 1 and channel 2 of the AMS controller. This provides for
redundancy so that failure of an individual sensing element will have no effect
on cockpit temperature control.
Using feedback from the temperature selector and the temperature sensors
the AMS controller will then change the left air conditioning pack outlet
temperature to achieve the desired cockpit zone temperature.
The AMS controller compares the selected cockpit temperature to the actual
cockpit zone temperature. The difference between the selected temperature
and the actual cockpit temperature is used to calculate a target cockpit zone
duct temperature. The AMS controller will then modulate the left pack bypass
valve to meet the target cockpit zone duct temperature.
Temperature sensors located in the forward and aft cabin zone and in the
forward and aft cabin ducts provide actual temperature via electronic signals
to the AMS controller.
The AMS controller compares the selected zone temperatures to actual zone
temperatures. The difference between the selected temperature and the
actual zone temperature is used to calculate a target duct temperature for
both the forward and aft cabin zone ducts. The AMS controller will then
modulate the right pack bypass valve, via the torque motor command, to
meet the coldest cabin duct target temperature. The trim bypass valve for the
coldest zone will be sent a signal to close. The AMS controller will then
modulate the opposite zone trim modulating valve to meet the warmest cabin
duct target temperature.
The trim air system utilizes two trim air modulating valves, two hot air
ejectors, and associated ducting to independently control the air temperature
entering the forward and aft passenger cabin distribution ducts. This is
accomplished by mixing hot air from the ejectors directly into the forward and
aft distribution duct openings within the mixing duct. The amount of hot air
flowing to the ejectors is controlled electronically by the AMS controller
through modulation of two trim air modulating valves.
The passenger cabin temperature is selected by the flight crew using the
PAX CABIN selector on the AIR COND / PNEUMATIC control panel. The
forward and aft passenger cabin zone temperatures can be selected by the
flight attendant using CABIN TEMPERATURE selectors located on the
attendant control panels.
The passenger cabin zone requiring the coldest air is controlled by
modulation of the right pack bypass valve. The opposite zone (warmest zone)
temperature is controlled by modulation of the trim air modulating valve
related to that zone.
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 154
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
AUTOMATIC TEMPERATURE CONTROL
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 155
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
DIAGNOSTIC AND TEST
TEMP CONTROL AND TRIM CONTRL PARAMETERS
This CMC page provides PACK health monitoring, by monitoring
temperatures at different stages of the air cycle machine. Diagnostic page
also shows the selected and actual flight deck and passenger cabin
temperatures. Second diagnostic pages provide valve position for monitoring.
For example 15 different status for AMS( bleed valve ) position.
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 156
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
CMC DIAGNOSTIC
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 157
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
ATA 21-00 MEL
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 158
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
MEL - EXAMPLE
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 159
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
MEL - EXAMPLE
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 160
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
MEL - EXAMPLE
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 161
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
MEL - EXAMPLE
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 162
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
MEL – EXAMPLE
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 163
Embraer ERJ-190 Series (GE CF34)
B1.1. and B2
ATA 21
AIR CONDITIONING
THIS PAGE IS INTENTIONALLY LEFT BLANK
ISSUE 1, 24 Sep 2014
FOR TRAINING PURPOSES ONLY
Page: 164