Aerosphere Midibus
Air Conditioning System
Operation Manual
Aerosphere Midibus
05/2013
P.N. 10000038A
To receive the best performance from the air conditioning system, we
suggest carefully reading this manual before operating the unit.
Keep this manual in the vehicle for future reference.
Aerosphere Midibus
Table of Contents
12-
3-
4-
567-
INTRODUCTION……………………………………………………………………………….
SAFETY PRECAUTIONS……………………………………………………………………...
SPECIFIC WARNINGS………………………………………………………………………...
EQUIPMENT GENERAL ARRANGEMENT…………………………………………………
1.1 - MIDIBUS AIR CONDITIONING COMPONENTS…………………………………..
CONTROLS AND INDICATORS……………………………………………………………...
2.1 - FUNCTION OF THE DIGITAL DASH CONTROL …………………………………
2.2 - FUNCTION OF THE DIGITAL DASH CONTROL AND INDICATOR……….……
EQUIPMENT OPERATION……………………………………………………………………
3.1 - COMMAND DESCRIPTION – NORMAL OPERATION……………………………
3.2 - COMMAND DESCRIPTION – FAILURE MODE……………………………………
3.3 - COMMAND DESCRIPTION – TEST MODE………………………………………..
3.4 - ELECTRICAL MALFUNCTIONS……………………………………………………..
3.5 - AIR CONDITIONING SYSTEM MALFUNCTIONS…………………………………
3.6 - REFRIGERATION CIRCUIT MALFUNCTIONS…………………………………….
PREVENTIVE MAINTENANCE ACTIVITIES………………………………………………..
4.1 - GENERAL………………………………………………………………………………
4.2 - AUXILIARY DATA VISULIZATION MODE………………………………………….
4.3 - PREVENTIVE MAINTENANCE SCHEDULE……………………………………….
TECHNICAL SPECIFICATIONS………………………………………………………………
FAILURE DIAGNOSIS TABLE………………………………………………………………..
ELECTRICAL SCHEMATICS OF RELAY BOARD AND DIGITAL DASH CONTROL….
7.1 - RELAY AND FUSE LOCATION………………………………………………………
7.2 - RELAY BOARD (GL-W134) CONNECTIONS………………………………………
7.3 - RELAY BOARD FUNCTION LED’s………………………………………………….
7.4 - SCHEMATIC FOR DIGITAL DASH CONTROL AND RELAY BOARD…………..
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Aerosphere Midibus
INTRODUCTION
At Spheros, we develop our products with the goal of providing a comfortable environment for vehicle passengers. We are always
looking for the best air condition concepts that provide the highest performance at the best possible value.
The compact systems are simple to operate and provide high cooling capacities at low noise levels.
This manual was developed with the purpose of presenting critical functional aspects, describing the ease of operation and
recommended maintenance necessary to obtain the best performance from the Spheros Air Conditioning system.
To ensure a long, useful and problem free life from the equipment it is essential that the operation and maintenance instructions
described in this manual are followed routinely and thoroughly.
All system controls provided by Spheros, are duly illustrated and explained in this manual.
It is important that the operator reads and understands the operation instructions carefully before starting the air conditioning
equipment.
Spheros makes every effort to maintain a network of authorized service professionals trained to perform any type of maintenance
within the quality standard.
Thank you for choosing Spheros Air Conditioning products. If you have any questions or concerns with our products, please contact
us or the nearest authorized service provider.
Spheros Climate Systems, LLC
5536 Research Drive
Canton, MI 48188
Phone 1-734-218-7350 Toll free 1-888-960-4849
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Aerosphere Midibus
SAFETY PRECAUTIONS
GENERAL SAFETY NOTICES
The following safety notices supplement warnings and cautions appearing elsewhere in this manual. The following are
recommended precautions that must be understood and applied during operation and maintenance of the equipment. Failure to
adhere to warnings and cautions may result in damage to equipment, fire, personal injury and even death.
OPERATING PRECAUTIONS
Keep hands, clothing and tools clear of the evaporator and condenser fans.
No work should be performed on the system unless battery power is disconnected.
In case of severe vibration or unusual noise, stop the system and investigate.
MAINTENANCE PRECAUTIONS
Always wear protective eye wear (safety glasses or goggles) and appropriate safety wear.
Never perform any maintenance or service on your equipment before consulting with authorized service personnel. Always unplug
unit before attempting any maintenance.
Avoid breathing any refrigerant vapor, lubricant vapor, or mist. Exposure to these, particularly PAG oil mist may irritate your eyes,
nose, or throat.
Never use compressed air (shop-air) to leak-test or pressure test a R134A system. Under certain conditions, pressurized mixtures of
R134A and air can be combustible. In addition, shop air will inject moisture into the system.
Always use mineral oil to lubricate “O” Rings, hoses, and fittings on R134A systems. PAG oils absorb moisture and become very
acidic and corrosive. Mineral oil does not absorb moisture and thus prevents corrosion. Always wear gloves when working with PAG
(Polyalkylene Glycol) and Ester (POE or Polyester) lubricants to prevent irritation to your skin. R134A lubricants can damage
vehicles paint, plastic parts, engine drive belts and coolant hoses.
Beware of unannounced starting of the evaporator and condenser fans. Do not remove the evaporator/condenser cover without
disconnecting the vehicle battery cable. Be sure power is turned off before working on motors, controllers, and electrical control
switches. Tag system controls and vehicle battery to prevent accidental energizing of the system.
In case of electrical fire, extinguish with CO2 (never use water). Disconnect vehicle battery power if possible.
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Aerosphere Midibus
SPECIFIC WARNINGS AND CAUTIONS
WARNING
Be aware of unannounced starting of the evaporator and condenser fans. The unit may cycle the fans and compressor
unexpectedly as control requirements dictate.
WARNING
The refrigerant contained in the air conditioning system when in direct contact with skin and eyes can cause frostbite,
severe burns or blindness.
WARNING
Be sure to observe warning listed in the safety precautions in the front of this manual before performing maintenance
on the air conditioning system.
WARNING
Never use air for leak testing. Pressurized, air-rich mixtures of refrigerants and air are combustible when
exposed to ignition source.
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Aerosphere Midibus
SPECIFIC WARNINGS AND CAUTIONS
WARNING
Do not use a nitrogen cylinder without a pressure regulator. Do not use oxygen in or near a refrigeration
system as an explosion may occur.
WARNING
The filter-drier may contain liquid refrigerant. Slowly open the fitting nuts and avoid contact with exposed
skin or eyes.
CAUTION
Unless there was a catastrophic failure, such as a blown or ruptured refrigerant hose, additional oil may
not be needed.
CAUTION
Use only the exact oil specified by the compressor manufacturer. Use of oil other than that specified will
void the compressor warrant
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Aerosphere Midibus
1. Equipment General Arrangement
1.1 Midibus Air Conditioner Components
The Midibus air conditioner and its main components are shown in Fig. 1.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
Evaporator Blowers, Right
Electrical Interface with Fuse Array
Shut off Valve
Filter Drier
Sight Glass
Solenoid Valve
Receiver
Expansion Valve
Bleed Valve – Heater Core
Evaporator Blowers, Left
Heater Core
Evaporator
Air Filter
Condenser
Condenser Fan
Fresh Air Dampers
Main Relay Board
Heating Board
Fig. 1 – Main Components
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Aerosphere Midibus
2. Controls and Indicators
2.1 Functions of the Digital Dash Control Panel
The air conditioner control panel has all controls and indicators for system settings, mode switching and and provides visual
display of operation status. The control panel and its controls and indicators are shown in Fig. 2.
1
2
15
3
14
4
13
5
12
6
11
7
10
8
9
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
Internal/External Temperature Key
External Temperature LED
Display
Smart Air LED
Auto Mode Key
Auto Mode LED
Ventilation Speed LED’s
Ventilation Key
Reheat LED
Reheat Key
Fresh Air / Recirculated Air
Fresh Air LED
Down Key
Up Key
Internal Temperature LED
Fig. 2 - Digital Dash Control Panel
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Aerosphere Midibus
2.2
Function of Digital Dash Control and Indicators
The function of the controls and indicators is shown in Fig. 3. Note: All keys have backlit red LED’s,
Index Fig. 3
1
2
Control / Indicator
Internal / External
Temperature Key
External
Temperature Key
Setting / Indication
Pressed
Lit
°F
3
Display
Number or
Code
4
Smart Air
LED
Lit
5
AUTO Key
Pressed
6
7
AUTO Mode LED
Ventilation Speed
LED 1, 2, 3
Ventilation Key
Lit
1, 2,or 3 Lit
Lit
Pressed
Pressed
12
13
Reheat LED
Reheat Key
Fresh Air /
Recirculated Air Key
Fresh Air LED
Down Key
14
Up Key
Pressed
15
Internal Temperature
LED
Lit
8
9
10
11
Pressed
Lit
Pressed
Function
Selects internal or external temperature indication and displays
for 5 seconds.
External temperature indication selected and displays for 5
seconds.
Ignition on, system in standby for activation by pressing the
AUTO key.
Ventilation only is possible by pressing ventilation key.
Indication of temperatures, ventilation speed, failure codes and
status information depending on system operational mode and
indication selections. See “Command Description” for details.
Smart air mode on. In AUTO mode the system adjusts to best
comfort and thermal balance by opening fresh air damper for 10
seconds every 10 minutes
AUTO mode on or off. When on, system automatically controls
heating and/or cooling to obtain the set temperature.
With AUTO mode on, system operates in AUTO mode.
Indication of ventilation speed selected. AUTO mode LED is off.
Manual selection of blower speeds with up / down keys to
override AUTO mode ventilation speed.
Indication of Reheat mode selected.
Selects Reheat mode for cabin dehumidification.
Opens or closes fresh air damper to override AUTO mode fresh
air damper position.
Reheat Mode ON
Down control for system settings and readings of the
operational modes including testing and system status.
Up control for system settings and readings of the operational
modes including testing and system status.
Internal temperature indication selected and on display for
5 seconds.
Fig. 3 - Function of Controls and Indicators
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Aerosphere Midibus
3. Equipment Operation
3.1 Command Description – Normal Operation
Display
The two digit numeric display
is used for informing the operator about the selected set temperature. With the vehicle ignition
ON, the display will show °F/°C to indicate standby for A/C operation which can be activated by pressing the
key and selecting
the desired temperature. When AUTO mode is off, it is possible to have just ventilation by pressing the
key.
Automatic Mode
1 - To select the Automatic Mode press the
key. The display shows the set-point temperature and the system activates the
required function (cooling or heating) according to the internal temperature, external temperature, set-point and parameters.
2 – To disable the Automatic Mode, press the
key again.
Set-Point
The set-point is the desired temperature inside the vehicle. To change the set point temperature the AUTO mode must be selected.
The set-point temperature will be shown in the display and may be adjusted by pressing the
or
keys.
Auto Mode with Blower Speed Priority
In the AUTO mode the blower speed is determined automatically. The operator may set the blower speed manually as follows:
- Turn on the AUTO mode by pressing the
key.
- Press the
key. The blower speed will be shown on the display for a few seconds.
- If the operator presses the
or
key while the speed is displayed, the speed LED will come on indicating manual speed
mode.
- Use the
and
keys to select the desired speed.
- To return to automatic mode, press the
key.
This mode is useful when it is convenient to maintain a constant blower speed. It may be used for driving at night with sleeping
passengers at a constant blower speed of 1 to reduce the noise with a minimum A/C function.
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Aerosphere Midibus
Ventilation Mode
The Ventilation function is activated by pressing the
key.
There are three operation speeds. Press the
key and the speed will be shown and may be adjusted by pressing the
or
key. When you select the ventilation function, the fresh air damper (air renewal) is automatically opened. To close the
fresh air damper, the operator must press the
key and the
key.
SPEED
DISPLAY INDICATION
LED’s
Off
Low
Medium
High
Fig. 4 – Indication of Ventilation Mode
Internal / External Temperature
Press the
key - internal temperature (LED 15, Fig. 3)
Press the
key two times – external temperature (LED 2, Fig. 3)
The desired temperature will be displayed for 5 seconds.
The display will then return automatically to the set temperature.
Compressor
The compressor is activated based on temperature, the pressure switches and programmed values of the set-point. The compressor
will start 10 seconds after the condenser motors are activated.
The controller provides a fixed time delay of 60 seconds for restarting the compressor. When the external temperature is below
59°F/15°C in cooling mode, the system tries to cool down with fresh air and the clutch may be disengaged.
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Aerosphere Midibus
Condenser Motors
The condenser motors will start every time there is the need to turn on the compressor.
They will always run for 10 seconds before the compressor clutch is engaged.
System Pressure Switches
The system monitors pressure by means of a high and low pressure switch in series with the clutch. In case of a pressure failure, the
clutch will be disengaged immediately. The system will detect a failure after 2 seconds and will start indicating
on the display
alternating with the temperature reading.
Once the pressure fault disappears and the AUTO mode is on and the other conditions have been met, the system will delay for 3
minutes before allowing the compressor to start. This failure condition is constantly monitored whether system is on or off.
If the failure occurs 6 times or more within 30 minutes, the
alarm will be activated to indicate a serious system failure and A/C
operation will not be allowed. To reset the system it will be necessary to turn the vehicle ignition off and then on again.
Evaporator Freeze Protection
The system is monitored by a thermostat which senses icing of the evaporator coil. When the thermostat responds (opens contacts)
the compressor clutch disengages and the evaporator motors remain on to allow the coil to defrost.
While the thermostat is activated, the display will show the failure code
alternating with the temperature display. After defrosting
the thermostat will return to normal operation. With the AUTO mode ON the system will delay for 3 minutes before the compressor
will restart.
Evaporators
The system controls an evaporator with 3 speed blowers. The blowers always start in Low speed in the AUTO mode and if
necessary the speed is increased to the calculated speed. This extends the blower’s life and reduces the noise level.
The control of the evaporator motor speed is automatic according to the temperatures in the AUTO mode. When the temperature
approaches the set temperature, speed is reduced and increased again in order to approach the set temperature (except in heating
mode).
Roof Heating (optional)
Heating will only be available when unit is equipped with a heating board. A valve controls the flow of hot water passing through the
heater core. A water pump is turned on each time the valve is opened to a certain extent. When in the heating mode, the blowers
always work at LO speed in AUTO mode. If necessary, it is possible to change the speed manually to MED or HI.
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Aerosphere Midibus
Fresh Air / Air Recirculation
There are two system operation modes:
- Smart Air
- Manual Mode (temporary)
Fresh air operates in both modes. The Smart mode automatically controls operation according to the temperature conditions of
internal, external and for exchanging the air inside the vehicle. The manual mode allows the driver to control the external air quantity
manually.
When the AUTO mode is activated, Smart Air is selected as indicated on the control panel by the Smart Air LED. This function
enables air renewal to operate so it adjusts to meet comfort and thermal balance conditions as well as saving fuel. To change the
fresh air damper position press
, the control panel will show the damper position.
INDICATION
FRESH AIR
Open
Closed
When the fresh air damper position is shown, press
to open or
to close the fresh air damper. The display point will disappear
and the manual mode is initiated. After 10 minutes the system returns to the Smart Air mode of operation.
In the Smart Air mode the fresh air damper opens and closes automatically with the air damper open for 10 seconds every 10
minutes. This will only occur when the internal temperature sensor senses between 3° over and 3° below the set temperature.
Reheat Mode (optional with roof heating)
This mode only operates when heating is included in the system. This mode enables dehumidification inside the vehicle. To turn on
Reheat press the
key and the mode will be active for 10 minutes. During reheat operation the fresh air damper is closed. If the
driver tries to open the fresh air damper and the system refuses, the panel will display
.
In the reheat mode the air conditioning system is activated including the condenser, evaporator and compressor. At the same time
the roof duct heating is enabled to reach the set temperature. The simultaneous operation of both the air conditioning system and
the roof system is how dehumidification is accomplished.
This mode operates only when the set-point temperature is higher than or is equal to the internal temperature and the external
temperature exceeds 46°F/8°C. Any other condition prevents the driver from selecting the Reheat Mode. The display will show
when the external temperature is less than 46°F/8°C and
when the set-point temperature exceeds the internal temperature.
This mode of operation is particularly recommended in inter-seasonal periods when the air is extremely humid.
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Aerosphere Midibus
3.2 Command Description – Failure Operation
Failure Operation – Control Panel Functions
The system indicates failure codes on the display. The possible failure codes and their meanings are shown in Fig. 5.
FAILURE
POSSIBLE CAUSE
OPERATIONAL BEHAVIOR
Communication failure between control
panel and main relay board
Internal sensor failure
The system automatically activates the A/C AUTO function
using a previously stored set-point.
The system defaults at an internal temperature value of
71°F/22°C.
For heating the driver must program a set-point temperature
> 71°F/22°C.
If cooling is necessary, the driver must select a set-point
≤ 71°F/22°C.
Control takes place regarding the return air temperature, with
the parameter value equal to 0.
The system uses an external air temperature value of
71°F/22°C. The reheat and the smart air modes are disabled.
The condenser and compressor are turned off. When the
failure disappears the system is reactivated with a delay of 3
minutes.
The system will only operate in the ventilation or heating
mode. In order to start the A/C again, the control must be
reset by turning system off and back on.
The compressor and condenser fans are turned off. When the
coil is defrosted the system will delay for 3 minutes and
resume operation.
All functions are disabled. To restore operation press the auto
key and 10 seconds later press auto key again.
The compressor and condenser are turned off and system
operates in low speed ventilation mode. When the alternator
reaches the normal range the system will resume operation.
All functions are disabled. To restore operation press the auto
key and 10 seconds later press auto key again.
When temperature rises above 46°F/8°C the system will
resume operation.
Air duct sensor failure
External sensor failure
Pressure switch failure
Pressure switch failure occurred 6
times within 30 minutes
Icing of the evaporator coil
Alternator voltage above 33 Volts
Alternator voltage below 21 Volts
Alternator voltage below 18 Volts
External Temperature below minimum
of 46°F/8°C with reheat mode enabled.
Fig. 5 - Failure Code Indications
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Aerosphere Midibus
3.3 Command Description – Test Operation
This mode is used to diagnose the system by checking the inputs (Fig. 6) and activating the outputs (Fig. 7). To access this mode,
perform the following steps:
-
Press the keys
+
. The display will indicate --, asking for the access password. The access password is “14”.
Use the
key for increasing the first digit and the
key for decreasing the second digit until the correct password is displayed.
Press
to confirm. If the password is incorrect, the display will indicate the vehicle internal temperature. After verifying the
password, the display will indicate for inputs to be tested.
Press
for alternating between the inputs and the outputs.
By pressing the
key, the display will indicate
or
, depending on whether it is an input or an output. When it is an input
the ventilation LED speed 2 will display the input status. If it is blinking the input is “off” and not blinking indicates “on”.
When you select an output , press
to turn it on and/or off. The ventilation LED speed 2 will be on indicating output is on.
Press
or
for alternating between other inputs or outputs. When you alternate the output function, the previous function will
be turned off.
Press
to exit a selected input or output mode and move to another or press
the second time to exit the test mode.
The function
allows the A/C system to operate without considering internal temperature. This function is used when it is
necessary to turn on the A/C for testing when the temperature inside the bus will not allow the A/C to operate. All other protections
are enabled in this mode.
INPUT
LED “ON”
LED “BLINKING”
Pressure Switches Input
DESCRIPTION
Both Pressure switches are OK
or in the closed position
Evaporator coil Ice Sensor Input
Ice Sensor OK
Input indicating the Heating system
is enabled
Heating control board GL-W002
is installed, enabled and
operating
One or both Pressure Switches in fail
status or in the open position. Check
connections and pressure switches.
Ice sensor indicates that the
evaporator coil is blocked with ice.
Check Ice Sensor and connections.
Heating control board GL-W002 not
installed.
Fig. 6 - Test Operation Input Readings
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Aerosphere Midibus
OUTPUT
DESCRIPTION
Turns blowers on at Low speed
Turns blowers on at Medium speed
Turns blowers on at High speed
Opens air flap
Turns on fans (condenser motors)
Turns on water pump
Opens heating valve (30%) (If heating option is installed)
Opens Heating valve (65%) (If heating option is installed)
Opens Heating valve (99%) (If heating option is installed)
Refrigerant charge function, allows refrigeration to take place independently of the control conditions
Fig. 7 – Test Operation Output Readings
3.4 Electrical Malfunctions
The individual circuits are to be checked systematically in accordance with the wiring diagram. The plug connections and electrical
components such as switches, relay, etc. should be checked.
The following are possible causes of electrical malfunctions and should always be checked first so they can be excluded as the
cause of the failure:
- Corroded plug contacts
- Loose plug contacts
- Corroded wires
- Corroded battery terminals
- Broken wires
- Defective fuses
3.5 Air Conditioning System Malfunctions
The following failures may occur in the air conditioning system and may lead to a fault lockout of the system:
- Activated freeze protection sensor
- Activated high / low pressure switch
- Defective compressor
- Defective evaporator or condenser fans
- Refrigerant loss due to leaks
- Plugged air filter or dirty heat exchanger fins
- Restricted refrigeration circuit (filter drier)
- Defective expansion valve
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Aerosphere Midibus
3.6 Refrigeration Circuit Malfunctions
If malfunctions occur in the refrigeration circuit of the air conditioning system, the system must be checked and properly repaired by
an authorized air conditioning service professional.
CAUTION
The refrigerant is not allowed to be released to the atmosphere. Regulatory requirements mandate that individuals who
open a system or container containing a controlled refrigerant be certified.
Check the refrigerant charge in the system:
- After the air conditioning system has been operating for approx. 5 min. with the electromagnetic clutch activated and the engine
running at a rapid idle, the refrigerant should flow through the sight glass without forming any bubbles.
During the cold season:
- To prevent the shaft seal of the compressor from drying out and leaking, operate the air conditioning system for approx. 15 min.
twice a month at ambient temperatures above 46°F (8°C).
The refrigerant receiver as well as all components of the air conditioning system should be visually inspected during the maintenance
activities. Special attention should be directed to any signs of corrosion and mechanical damage.
All components that are not in perfect condition must be replaced for safety reasons.
CAUTION
The pressure vessels directive requires the operator to have the refrigerant receiver checked by an authorized service
professional at regular intervals.
Note
To ensure trouble free operation of the air conditioner, the refrigeration oil and filter drier must be replaced 6 months after the initial
operation of the vehicle or if there is a change in color of oil.
a) Yellow – Normal oil
b) Black – Carbonized oil
c) Brown – Copper Corrosion, due to moisture in system
d) Metallic Gray – Suspended metallic particles
The filter drier should be replaced every year at the beginning of the season or every time system is exposed to contamination.
These activities must be performed by an authorized service company which should also perform a functional check of the air
conditioner as well as a leak test of the system.
Warranty claims can only be accepted if the claimant can prove that the maintenance and safety instructions have been strictly
observed.
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Aerosphere Midibus
4. Preventative Maintenance Activities
4.1 General
An air-conditioning system just as all other parts of the vehicle subjected to constant mechanical strain and stress. To ensure
trouble-free operation of the system and to avoid any damage to its parts, it is important that all required service activities on the air
conditioning system are performed by trained and qualified personnel who are knowledgeable in the field of refrigeration.
The proper handling of the system including proof of the service activities record is a prerequisite for acceptance of any warranty
claims in the event of damage to parts subject to maintenance.
Warranty replacement parts and out of warranty replacement parts must be supplied by Spheros Climate System, LLC to assure
the quality and reliability of the product.
Regardless of the maintenance intervals specified in the maintenance and service schedule, all attachments of the unit and the
connections of the refrigerant lines must be checked for tightness within the first four weeks following the initial start-up of the airconditioning system or the vehicle.
Even if the air-conditioning system is not in operation, wear caused by normal aging or the strain and stress occurring during the
driving operation of the bus may occur on individual components. All checks listed in the maintenance and service schedule need to
be independent of the operation hours of the system.
Loss of refrigerant is possible even if the refrigerant connections are tight due to the structure of the material of the refrigerant lines
and the ambient temperatures. In the event of a relatively high refrigerant loss within short intervals, leaks in the system can be
assumed.
During long periods of non-use, the air-conditioning system should be operated for about 15 minutes at least twice a month in order
to prevent the shaft seals of the compressor from hardening.
The drive pulley of the electromagnetic clutch is continuously rotating when the vehicle engine is in operation. Bearing wear or
possible damage to the clutch may occur and should be inspected independently of maintenance intervals based on the operating
time of the air-conditioning system. It is imperative that the clutch be checked for correct lubrication, belt tension etc.
CAUTION
- The refrigerant receiver is subject to the Pressure Equipment Directive. Check the receiver every 6 months for cracks,
mechanical damage or corrosion. The receiver must be replaced if any defects are found.
- The maintenance intervals indicated in the maintenance and service schedule are based on the operation hours of the vehicle,
with the exception of the compressor assembly, which are based on the air-conditioning unit’s hours of operation.
- These time intervals are empirical values that may vary widely depending on the type of system and type of bus concerned
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Aerosphere Midibus
4.2 Auxiliary Data Visualization Mode
The system presents an auxiliary data visualization mode. For entering this mode, press the
display will indicate the first auxiliary
which is total hours of compressor operation.
and
keys for 3 seconds. The
Example:
Example indicates 129 thousand 128 hours of total compressor operating hours.
Press
or
keys to alternate between the various indications as listed in Fig. 8. To exit this mode press the
key.
The following table shows the Auxiliary Data Indications with their description:
INDICATION
DESCRIPTION
Total hours of compressor operation shown in the format 00 00 00
Alternator voltage displayed in VDC
Temperature of duct sensor for heating mode
Dash Control software version
Relay Control Board software version
Heating valve open positions (30%, 65%, 99%)
Fig. 8 – Auxiliary Data Indications
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Aerosphere Midibus
4.3 Preventive Maintenance Schedule
All preventive maintenance described below is based on typical operating conditions. The frequency outlined below is for
normal operating conditions and should increase if used under more sever conditions.
COOLING CIRCUIT
Measure and record the refrigerant pressures and temperatures of the suction line
Measure and record the refrigerant pressures and temperatures of the liquid line
Visually inspect for signs of oil or refrigerant leaks
After 15 minutes of operation check refrigerant level using the sight glass
Visually inspect all components, tubes and hoses for signs of wear and deterioration
Change the filter drier once a year or each time the system is opened
Check the opening and closing pressures of the high and low pressure switches
COMPRESSOR / CLUTCH
Visually inspect the clutch plate
Visually inspect the condition, tension and alignment of the compressor belts
Clean the compressor and clutch with steam or hot water
Measure the resistance and the voltage on the clutch coil
Check the compressor oil level after 15 minutes of operation
STRUCTURE
Visually inspect for loose parts, damaged or broken wires
Clean or replace the return air filters
Clean the condenser and evaporator drains
Clean the fins the evaporator and condenser coils with coil cleaner or soap and water
Retighten all bolts on the compressor support and the unit using recommended torque
MONTHLY
ANNUALLY
X
X
X
X
X
MONTHLY
QUARTERLY
X
ANNUALLY
X
X
X
X
MONTHLY
X
X
QUARTERLY
ANNUALLY
X
X
MONTHLY
Check control panel operation, clean panel and thermostat sensor with air
Check the alternator for corrosion and inspect electrical connections
Visually check the alternator belt tension, check for mis-alignment and wear
X
Check the power cable at the relay plate, re-torque if necessary
Inspect all wires and terminals for damage and corrosion
X
Check the ventilation of the condenser and evaporator motors
Note: We recommend using this table to develop a plan for routine maintenance to you A/C System
ELECTRICAL SYSTEM
QUARTERLY
X
X
QUARTERLY
ANNUALLY
X
X
X
X
19
Aerosphere Midibus
IMPORTANT: The return air filter and the condenser coil must be checked and cleaned weekly. As a rule, the air ducts must be
cleaned every 3 months and more frequently depending on operating times of the system, the number of passengers and the
severity of the environmental conditions.
A cost effective preventive maintenance program can prevent costly down time and repairs and avoid cancellation of
warranty due to negligence.
5. Technical Specifications
The main specifications for the air conditioning system are shown in Fig. 9.
Technical Data
Max. Cooling Capacity (BTU/H) / (KW)*
Heat Output (BTU/H) / (KW)*
Dimensions: Length x Width x Height (in) / (mm)
Weight (lbs) / (kg)
Evaporator Air Flow (CFM) / (m³/h)
Maximum Outside Temperature (°F) / (°C)
Supply Voltage (VDC)
Current Consumption @ 24 VDC / 12 V (AMPS)
Refrigerant Type
Number of Evaporator Blowers
Number of Condenser Fans
Aerosphere Midi
85,304 / 25
102,364 / 30
90.6 x 72.5 x 8.3 / 2,300 x 1,840 x 210
298 /135
2,472 / 4,200
140 / 60
24V
70A
R-134A
4
3
*Evaporator air in 104°F / 40°C, 46% RH, Ambient 95°F / 35°C.
Fig. 9 - Technical Data
20
Aerosphere Midibus
6. Failure Diagnosis Table
As a troubleshooting aide, the table in Fig. 10 lists possible failure symptoms, possible causes and solutions to assist in correcting
the problem.
Symptoms
Compressor does not work
HP switch opens
LP switch opens
Condenser Fan not working
Evaporator Blower not working
Possible Cause
Fuse or relay defective
Magnetic clutch burned
Compressor locked
Low pressure switch open
Overcharge of refrigerant
Condenser coil dirty
Condenser fan(s) not working
Faulty HP switch
Loss of refrigerant
Plugged or defective expansion valve
Dirty evaporator coil
Dirty air filter
Evaporator blower(s) not working
Faulty low pressure switch
Electrical wiring connection bad
Burned fuse or defective control relay
Open winding in motor
Electrical wiring connection bad
Burned fuse or defective control relay
Open winding in motor
Solution
Replace fuse or relay
Replace clutch
Replace compressor
Low on refrigerant or defective pressure switch
Adjust refrigerant charge
Clean condenser coil
Replace fan(s)
Replace HP switch
Check for possible leak, adjust charge
Replace the expansion valve
Clean the evaporator coil
Clean or replace air filter
Replace blower(s)
Replace low pressure switch
Locate and repair connection
Replace fuse and/or relay
Replace fan
Locate and repair connection
Replace fuse and/or relay
Replace blower
Fig. 10 - Failure Diagnosis Table
21
Aerosphere Midibus
Symptoms
AC does not cool and
Compressor remains on
AC cools down too much and
Compressor continues to run
High discharge pressure
Possible Cause
Low on refrigerant charge
Non-Condensables in system
Plugged or defective expansion valve
Dirty evaporator coil
Dirty air filters
Incorrect temperature set point selection
Temperature sensor location
Overcharge of refrigerant in system
Restriction in sealed system
Condenser fan not working
Low suction pressure
Dirty condenser coil
Low system charge
Return air temperature too low
Plugged or defective expansion valve
Evaporator Blower(s) not working
Restriction in sealed system
Dirty air filters
Dirty evaporator coils
Solution
Check for leaks, adjust charge
Evacuate the unit to 1000 microns or less
and adjust charge to correct amount
Replace the expansion valve
Clean the coil
Clean or replace air filters
Adjust desired set point temperature on
control panel
Check and relocate temperature sensor
Adjust charge to correct amount
Locate and remove restriction, compressor
valve partially closed, expansion valve
partially closed, filter drier plugged
Refer to symptom “Condenser Fan not
Working”
Clean condenser coil
Check for leak, adjust charge
Relocate temperature sensor
Replace the expansion valve
Refer to symptom “Evaporator Blower(s) not
Working
Locate and remove restriction
Clean or replace air filters
Clean evaporator coils
Fig. 10 - Failure Diagnosis Table
22
Aerosphere Midibus
7. Electrical Schematics of Relay Board (GL-W134) and Digital Dash Control (GL-W111)
7.1 Relay and Fuse Location
GL-W134
RELAY
RL1
RL2
RL3
RL4
RL5
RL6
RL7
RL8
RL9
RL10
RL11
RL12
RL13
FUNCTION
Condenser Fans 1 & 2
Condenser Fan 3
Clutch
Evaporator Blower 3 & 4 HI
Evaporator Blower 3 & 4 LO
Evaporator Blower 3 & 4 MED
Evaporator Blower 1 & 2 HI
Evaporator Blower 1 & 2 MED
Evaporator Blower 1 & 2 LO
Evaporator Blower 5 & 6 LO
Evaporator Blower 5 & 6 MED
Evaporator Blower 5 & 6 HI
Condenser Fans 4 & 5
TYPE
FUSE
F1
F2
F3
F4
F5
F6
F7
F8
F9
F10
F11
F12
FUNCTION
Condenser Fan 2
Condenser Fan 1
Condenser Fan 3
Clutch
Evaporator Blower 3
Evaporator Blower 4
Evaporator Blower 1
Evaporator Blower 2
Evaporator Blower 5
Evaporator Blower 6
Condenser Fan 5
Condenser Fan 4
TYPE
15A
15A
15A
10A
15A
15A
15A
15A
15A
15A
15A
15A
23
Aerosphere Midibus
7.2 Relay Board 1101742A (GL-W134) Connections
CN9
CN8
CN1
CN5
CN6
CN7
CN3
GL-W134
CN4
CN1
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
+24Vdc After Ignition + Ext. Relay
Serial Data Com. 1
Serial Data Com. 2
Duct Temperature Sensor
Internal Temperature Sensor
Command Blower Med. Speed
+24Vdc After Ignition + Ext. Relay
GND
N.C.
Duct Temperature Sensor
Internal Temperature Sensor
External Temperature Sensor
Note: CN3 Communicates with the
GL-W004 Heating Module
CN3
1.
2.
3.
4.
5.
6.
7.
8.
9.
CN4
Command Blower LO
Command Clutch
Address Relay Board
Command Blower MED
Command Fan
Serial Data Com. 3 (GL-W004)
Command Blower HI
GND
Command Fresh Air
CN7
1.
2.
3.
4.
5.
6.
7.
8.
9.
CN10
+24Vdc Blower 1
N.C.
+24Vdc Blower 2
Blower 1 HI
Blower 1 LO
Blower 1 MED
Blower 2 HI
Blower 2 LO
Blower 2 MED
1.
2.
3.
4.
5.
6.
7.
8.
9.
Condenser Fan 3
N.C.
N.C.
Condenser Fan 1
N.C.
Condenser Fan 4
Condenser Fan 2
N.C.
Condenser Fan 5
1.
2.
3.
4.
5.
6.
7.
8.
9.
CN10
1.
2.
3.
4.
5.
6.
7.
8.
9.
+24Vdc Blower 5
N.C
+24Vdc Blower 6
Blower 5 HI
Blower 5 LO
Blower 5 MED
Blower 6 HI
Blower 6 LO
Blower 6 MED
CN6
CN5
Pressure Switches
Ice Sensor
Clutch
+24Vdc Direct Battery
Ice Sensor
Pressure Switches
+24Vdc After Ignition
GND
N.C.
1.
2.
3.
4.
5.
6.
7.
8.
9.
CN8
1.
2.
3.
4.
5.
Connection for
Fresh Air Module GL-D012
+24Vdc Blower 3
N.C.
+24Vdc Blower 4
Blower 3 HI
Blower 3 LO
Blower 3 MED
Blower 4 HI
Blower 4 LO
Blower 4 MED
CN9
1.
2.
Fresh Air Motor
Fresh Air Motor
24
Aerosphere Midibus
7.3 Relay Board 1101742A (GL-W134) Function LED’s
LED
CD
CL
EL
EM
EH
FUNCTION
CONDENSER FAN
CLUTCH
EVAPORATOR BLOWER LOW
EVAPORATOR BLOWER MEDIUM
EVAPORATOR BLOWER HIGH
COLOR
GREEN
GREEN
GREEN
GREEN
GREEN
OPERATION
ON WHEN OPERATING
ON WHEN OPERATING
ON WHEN OPERATING
ON WHEN OPERATING
ON WHEN OPERATING
RELAY
1, 2, 13
3
5, 9, 10
6, 8, 11
4, 7, 12
GL-W134
LED
RUN
TX
RX
COLOR
RED
RED
RED
OPERATION
SEE RUN TABLE
BLINKING –TRANSMITTING DATA TO DASH CONTROL
BLINKING – RECEIVING DATA FROM DASH CONTROL
O
☼
☼
●
RUN TABLE
CPU NOT WORKING
1HZ: NORMAL OPERATION
3HZ: SYSTEM FAIL
CPU NOT WORKING
25
Aerosphere Midibus
7.4 Electrical Schematic for Digital Dash Control (GL-W111) to Relay Board GL-W134
CN2
CN2
1.
2.
3.
4.
5.
6.
7.
8.
9.
Serial Data Com 1
GND
Convector Monitor. Input
Serial Data Com 2
N.C.
Air Flow Barrier (Optional)
+24 VDC After Ignition
Engine Increase RPM (Optional)
N.C.
CN1
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
+24Vdc After Ignition + Ext. Relay
Serial Data Com. 1
Serial Data Com. 2
Duct Temperature Sensor
Internal Temperature Sensor
Command Blower Med. Speed
+24Vdc After Ignition + Ext. Relay
GND
N.C.
Duct Temperature Sensor
Internal Temperature Sensor
External Temperature Sensor
26
Aerosphere Midibus