SECTION 23 09 93
SEQUENCE OF OPERATION FOR HVAC CONTROLS
PAGE 1 OF 15
SECTION 23 09 93
SEQUENCE OF OPERATIONS FOR HVAC CONTROLS
PART 1 - GENERAL
1.01
SECTION INCLUDES
A.
1.02
1.
Control devices.
2.
Air handling units.
3.
Fan coil units.
4.
Makeup air unit control.
5.
Heating coils.
6.
Boiler plant.
7.
Cabinet heaters.
8.
Unit heaters.
9.
Radiant panels.
10.
Radiation
11.
Hot water heater control domestic.
12.
Exhaust fans.
13.
Emergency generators.
14.
Duct mounted smoke dampers.
15.
Excess pressure controls.
16.
General alarm status monitoring.
RELATED DOCUMENTS
A.
Drawings and general provisions of Contract, including General and Supplementary
Conditions and Division-1 Specification sections, apply to work of this section.
B.
The Following Division 15 Specifications Sections apply to the work of this section
C.
102313
Sequence of operation for mechanical systems and components:
1.
Section 23 09 23 - Direct Digital Control Equipment.
2.
Section 23 09 00 - Instruments and Control Elements
The requirements of Division 26 - Electrical apply to work of this section.
PROJECT NO. BI-RT-844-CMR
SECTION 23 09 93
SEQUENCE OF OPERATION FOR HVAC CONTROLS
PAGE 2 OF 15
1.03
SYSTEM DESCRIPTION
This Section defines the manner and method by which controls function. Requirements
for each type of control system operation are specified. Equipment, devices, and system
components required for control systems are specified in other Sections.
1.04
SUBMITTALS
A.
Refer to Section 23 09 23 - Direct Digital Control Equipment
B.
Submit in accordance with Division 1 and Section 23 04 00.
Submit diagrams indicating mechanical system controlled and control system
components. Label equipment and control devices using the nomenclature on the
drawings. Control devices shall be labeled with settings, adjustable range of control and
limits. Include written description of control sequence.
D.
Include flow diagrams for each control system, graphically depicting control logic.
Include draft copies of graphic displays indicating mechanical system components,
control system components, and controlled function status and value.
Include wiring schematics of each control panel clearly showing extent of internal and
external wiring. Provide detail of panel face including controls, instruments, gauges and
labels. Indicate factory and field wiring.
Indicate each control panel required, with internal and external piping and wiring clearly
indicated. Provide detail of panel face, including controls, instruments, and labeling.
Include verbal description of sequence of operation.
Maintenance Data: Include copy of shop drawings in each maintenance manual; in
accordance with requirements of Division 1.
Project Record Documents: Accurately record actual locations, setpoints and settings of
controls, including changes to sequences made after submission of shop drawings.
PART 2 - PRODUCTS
Not Used
PART 3 - EXECUTION
3.01
GENERAL
Provide all controls, low voltage control wiring and accessories necessary to accomplish
the sequence of operation as indicated below. Power wiring and interlockwiring shall be
provided in accordance with Division 16 wiring requirements.
All sequences shall be performed by the Building Management System (BMS) unless
noted as a being controlled locally or specifically noted as controlled by other systems.
102313
PROJECT NO, BI-RT-844-CMR
SECTION 23 09 93
SEQUENCE OF OPERATION FOR HVAC CONTROLS
PAGE 3 OF 15
3.02
CONTROL DEVICES
A.
3.03
All devices and sensors shall be adjustable. BMS shall display setpoints and actual
conditions of all control devices and position of all actuators at the central personal
computer (PC).
AIR HANDLING UNITS & HEATING/VENTILATING UNITS (AHU-A1, RTU-#, ERV-#, HX-#)
A.
Unoccupied Mode:
1.
Outside air, exhaust air and relief air dampers shall be closed.
2.
Return air dampers shall be open.
3.
Fans and energy recovery motors shall be deactivated.
4.
BMS shall raise the zone temperature cooling setpoint to 85°F and drop the zone
temperature heating setpoint of 65°F. If two or more zones are calling for
heating or cooling the fans shall cycle on. When the call for heating or cooling is
satisfied the fans shall be deactivated.
5.
Compressors disabled and hot water valves shall be closed. If outside
temperature is below 40°F, unoccupied mode heating valve shall be fully open.
6.
Freezestat and temperature sensor within the unit's casing shall be monitored
during unoccupied mode. If temperature drops below setpoint of either device,
the main heating valve shall be fully open, fans shall be de-activated and an
alarm shall be activated at the central PC.
7.
B.
C.
102313
If an occupied button is depressed on a zone temperature sensor then the unit
shall leave the unoccupied mode for 2 hours.
Occupied Mode:
1.
The zone will calculate how long it will take to return from its unoccupied state to
its occupied setpoint based on the heating or cooling capacity and the outside air
temperature. The zone will then adjust its effective setpoint at the time
necessary in order to ensure the desired zone conditions at occupancy.
2.
The system will not start more than 4 hours before a scheduled occupancy.
3.
BMS shall track the supply fan's accumulated runtime. When runtime exceeds
10,000 hours, the controller will generate a runtime expiration message.
4.
Fans shall operate continuously. Energy recovery motors shall be energized
5.
Outside air and relief air dampers shall be at minimum open positions.
Coordinate setpoints of motorized dampers serving outside air and relief air
dampers with air balancer.
Fan Control:
1.
When called to run, the fan will run for a minimum of 5 minutes.
2.
When the fan cycles off, it will remain off for a minimum of 5 minutes.
PROJECT NO, BI-RT-844-CMR
SECTION 23 09 93
SEQUENCE OF OPERATION FOR HVAC CONTROLS
PAGE 4 OF 15
Alarm Conditions:
Current sensing relays/VFD feedback: If fan has been signaled to start and
feedback from respective relay or VFD does not indicate the fan has started after
30 seconds, unit shall be shut down and an alarm shall be activated at the
central PC. Conversely, if fan on status is detected while the fan is turned off, a
separate "Hand" alarm shall be activated at the central PC
Damper end switches: If end switch does not indicate respective damper is open
after 30 seconds, unit shall be shut down and an alarm shall be activated at the
central PC. Conversely, if a damper is indicated open, a separate "Hand" alarm
shall be activated at the central PC.
Duct mounted smoke detectors: When a detector is in alarm mode the fire alarm
system shall be notified, respective fans shall be de-energized and an alarm
shall be activated at the central PC.
If a freezestat trips, the hot water valve at the respective unit shall be fully open,
fans shall stop, outside air damper shall be fully closed and an alarm shall be
activated at the central PC.
The controller will generate an alarm if the zone temperature remains 4°F higher
than its cooling setpoint for 5 minutes. This alarm will not be enabled until the
zone has been running for 30 minutes.
The controller will generate an alarm if the zone temperature remains 4°F lower
than its heating setpoint for 5 minutes. This alarm will not be enabled until the
zone has been running for 30 minutes.
The controller will generate an alarm if the discharge air temperature remains
higher than 120°F with a hysteresis of 5°F for 5 minutes. This alarm will not be
enabled until the zone has been running for 30 minutes.
The controller will generate an alarm if the discharge air temperature remains
lower than 45°F with a hysteresis of 5°F for 5 minutes. This alarm will not be
enabled until the zone has been running for 30 minutes.
Supply Air Temperature Setpoint Control
BMS will run a cooling setpoint optimization algorithm and a heating setpoint
optimization algorithm simultaneously.
The initial cooling setpoint will be 55°F, with a minimum of 53°F and a
maximum of 72°F.
If any zones are still calling for cooling at the end of a 5 minute period,
the setpoint algorithm will respond by lowering the setpoint by I°F for
every zone requesting cooling.
If no zones are still calling for cooling at the end of a period, the setpoint
algorithm will respond by raising the setpoint by I°F.
The cooling setpoint algorithm will not adjust the cooling setpoint by
more than 2°F in any period.
The initial heating setpoint will be 82°F with a minimum of 72°F and a
maximum of 85°F.
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PROJECT NO. BI-RT-844-CMR
SECTION 23 09 93
SEQUENCE OF OPERATION FOR HVAC CONTROLS
PAGE 5 OF 15
If any zones are still calling for heating at the end of a 5 minute period,
the setpoint algorithm will respond by raising the setpoint by 2°F for
every zone requesting heating.
If no zones are still calling for heating at the end of a period, the setpoint
algorithm will respond by lowering the setpoint by 1 °F.
The heating setpoint algorithm will not adjust the heating setpoint by
more than 4°F in any period.
BMS shall determine the AHU supply air temperature setpoint based on the
number of heating requests and cooling requests the AHU is receiving.
If there are more cooling requests than heating requests coming into the
AHU, or if there are the same number of heating requests as cooling
requests, the AHU controller will use the cooling setpoint.
If there are more heating requests than cooling requests coming into the
AHU, the AHU controller will use the heating setpoint.
When the BMS switches from the heating setpoint to the cooling
setpoint, the setpoint control algorithm will ramp from the heating
setpoint to the cooling setpoint at a rate of 1°F/minute.
When the BMS switches from the cooling setpoint to the heating
setpoint, the setpoint control algorithm will ramp from the cooling setpoint
to the heating setpoint at a rate of 1°F/1.5 minute.
3.
F.
The user will be able to override the supply air temperature setpoint.
Heating Control
If the outside air temperature is less than 65°F with a 2°F hysteresis and the
outside air temperature is valid, BMS will allow heating based on outside air
conditions.
2.
If the outside air temperature reading is not valid, BMS will still allow heating.
Upon a call for heating, dampers at energy recovery units shall be modulated to
increase flow rate through the energy recovery section and reduce flow rate at
the energy recovery's bypass. Energy recovery modules shall be the first stage
of heating.
Upon a call for heating with the outside air is between 65°F and 40°F, BMS shall
modulate the hot water valve, with the face and bypass damper full open to the
coil, to maintain temperature setpoints if cooling has been off for at least 5
minutes.
Upon a call for heating with the outside air below 40°F outside air, the hot water
valve shall be fully open and the face and bypass damper shall be modulated to
maintain temperature setpoint if cooling has been off for at least 5 minutes.
The user will be able to lock the signal to the hot water valve.
The user will be able to lock the signal to the face and bypass damper.
Energy Recovery Modules (AHU-A1 exempt) - Frost Control: When outside air
temperature is below unit's individual specific setpoint, bypass damper at the
outside air side of the energy recovery module shall modulate open. If unit does
not have a damper at the outside air, relief air/exhaust air bypass damper at the
energy recovery module shall modulate open. Dampers shall modulate to
102313
PROJECT NO, BI-RT-844-CMR
SECTION 23 09 93
SEQUENCE OF OPERATION FOR HVAC CONTROLS
PAGE 6 OF 15
maintain discharge air temperature setpoint. Setpoint for each unit shall be
determined per Specification Sections 23 81 06.
Cooling Control
If the outside air temperature is greater than 60°F with a 2°F hysteresis and the
outside air temperature is valid, the AHU controller will enable cooling based on
outside air conditions.
If the outside air temperature reading is not valid, the AHU controller will still
enable cooling.
Upon a call for cooling, BMS shall stage the compressors, to maintain
temperature setpoints if heating been off for at least 5 minutes.
Economizer Control
BMS will allow economizer cycles to be activated based on outside air conditions
if the return air temperature and enthalpy is greater than the outside air
temperature and enthalpy with a hysteresis of 5°F, the outside air enthalpy is
less than 22 Btu/Ib with a hysteresis of 2 Btu/Ib, the outside air temperature is
less than 65°F with a hysteresis of 2°F, and the outside air readings are valid.
In addition to all AHU's, economizer cycles shall be programmed for all Heating
and Ventilating Units (ERV&HX units). Exhaust fans serving H&V units shall act
as relief air fans and shall be activated when there is a call for cooling and
permissive inputs allow economizer cycles to be activated. Economizer cycles
for H&V Units shall be base on return air and outside air temperature, not
enthalpy readings.
If the outside air readings are not valid, BMS will disable the economizer. The
user will be able to enable the economizer if the outside air readings are not
valid.
When economizer cycles are activated, energy recovery motors shall stop and
energy recovery bypass dampers shall open.
An economizer PID will modulate the economizer/ventilation dampers and relief
air/exhaust fans between minimum setpoint and 100% to maintain the zone
temperature at 2°F below the zone temperature cooling setpoint if heating has
been off for at least 5 minutes. The relief air fans and exhaust fans shall and
activated.
The user will be able to adjust all PID parameters (P, I, and D gains, loop
bias, and loop interval).
The user will be able to lock the economizer damper position.
The controller will limit the signal change sent to the economizer to 1%
every 2 sec. when increasing.
If the mixed air temperature drops below 45°F, the AHU controller will begin to
close the economizer to protect the coil. The controller will continue to close the
damper linearly until the temperature drops to 40°F, when the
economizer/ventilation damper will be 100% closed.
102313
PROJECT NO, BI-RT-844-CMR
SECTION 23 09 93
SEQUENCE OF OPERATION FOR HVAC CONTROLS
PAGE 7 OF 15
If the AHU loses flow or the freezestat trips, the AHU controller will close the
economizer dampers.
The AHU controller will generate an alarm if the mixed air temperature remains
lower than 45°F for 5 minutes with a 5°F hysteresis, This alarm will not be
enabled until the supply fan has been running for 30 minutes,
The AHU controller will generate an alarm if the mixed air temperature remains
higher than 90°F for 5 minutes with a 5°F hysteresis, This alarm will not be
enabled until the supply fan has been running for 30 minutes,
I,
Air Flow Monitoring Stations
Outside Air: BMS shall monitor the outside air flow station(s) and modulate the
outside air and relief air dampers to maintain minimum outside air flow setpoint.
Supply air and return air flow rates at fans shall monitored as shown on the
drawings,
Outside Air - Demand Control Ventilation
BMS shall monitor carbon dioxide (DO2) sensors for each zone (return air for DV
units and VAV zones for VAV units), If DO2 levels rise above setpoint (800ppm
DO2), the controller shall modulate the outside air and relief air dampers open an
alarm shall be activated at the central PC.
System shall have the capability of reducing the amount of outside air based
upon CO2 levels,
Space pressure control (Wood Shop - ERV-S5)
During economizer operating mode of the ERV, space pressure monitoring
devices shall continuously pole the space pressure and adjust the return air and
exhaust damper positions of the Dust Collection Unit (D-l) to maintain the
interior space pressure at -0.1" w.c.
Whenever the economizer cycle of ERV-S5 is not operating, the space pressure
monitoring devices shall be ignored and the D-1 dampers shall be in the 100%
recirculation (return to space) position.
3.04
VAV AIR HANDLING UNIT CONTROL SEQUENCES
A.
Refer to General AHU Control Sequences above for additional Sequences or Operation.
B.
Supply Air Static Pressure Control
When the fans have flow, the AHU controller will modulate the supply fan VFD
with a reverse acting static pressure PID to maintain the duct static pressure at
the static pressure setpoint (1,5" w,c,), When cooling is activated, the fan VFD
shall not be allowed to drop below a speed setting that will produce a flow rate
equal to the total of the minimum flow settings of all the VAV boxes served by the
respective unit,
2.
102313
The user will be able to lock the output signal to the supply fan VFD.
PROJECT NO, BI-RT-844-CMR
SECTION 23 09 93
SEQUENCE OF OPERATION FOR HVAC CONTROLS
PAGE 8 OF 15
If the supply static pressure remains 25% higher than setpoint for 1 minute, an
alarm shall be activated a the central PC.
BMS shall generate an alarm if the supply static pressure remains 25% lower
than setpoint for 5 minutes. This alarm will not be enabled until the supply fan
has been running for 2 minutes.
C.
Return Fan Tracking Control
The AHU controller will send the supply fan run signal to the return fan if the AHU
is called to run.
The return fan control logic is identical to that of the supply fan, and will produce
similar alarms.
If the return fan loses its run signal, the controller will set the return fan VFD
output to zero.
4.
3.05
The user will be able to lock the output signal to the return fan VFD.
UNIT HEATERS
Unit heaters shall be controlled locally. When temperature falls below thermostat
setpoint, unit heater's fan shall be energized.
3.06
CABINET HEATERS
Single temperature thermostat maintains constant space temperature by cycling unit fan
motor when the aquastat is satisfied.
3.07
DUCT MOUNTED SMOKE DAMPERS-RTU-C5&S5
Dampers shall be controlled by the fire alarm system. Dampers shall close when the
respective air handling unit is shutdown or when smoke is detected at damper's
respective duct mounted smoke sensor. Fire alarm system shall be capable of remotely
controlling position of damper and have remote indication of position of damper.
3.08
BOILER PLANT
Heating system startup shall be initiated by the Building Management System. (BMS)
Boilers shall be allowed to operate when outdoor temperature is below setpoint of 60
degrees F (adj.) and shall be disabled once outdoor temperature rises above 65 degrees
F (adj.).
Once enabled, boilers shall operate by integral controls which shall inherently include
boiler sequencing with all boilers wired in a cascade configuration from a single
controller. The plant shall also utilize and outdoor air temperature sensor to change the
system supply water temperature (SWT) setpoint as outdoor air temperature (OAT)
varies based on the following schedule:
102313
1.
Whenever OAT > 50°F, SWT shall be 120°F.
2.
Whenever OAT < 20°F, SWT shall be 180°F.
PROJECT NO, BI-RT-844-CMR
SECTION 23 09 93
SEQUENCE OF OPERATION FOR HVAC CONTROLS
PAGE 9 OF 15
SWT shall vary inversely proportional from 120°F to 180°F for OAT's between
50°F and 20°F.
The boiler(s) controller shall automatically equalize boiler runtime and adjust the firing
sequence intervals. All boiler operating parameters including but not limited to cascade
methods and system temperature operating setpoints shall be adjustable at the boiler
control module. System operating parameters shall be communicated via applicable
protocols for viewing at the BMS front end.
The secondary system pumps (boiler injection pumps) shall be enabled by the boiler
controller to run when the respective boiler is firing.
The primary system pumps shall vary operating speed by variable frequency drives fitted
on every pump. Both sets of primary pumps shall operate in a lead/lag configuration
where the lead pump is enabled to run at minimum speed whenever the boiler plant is
enabled. The lead pumps shall vary speed to maintain a constant differential pressure at
all times. If a fault condition occurs with a lead pump at any time an alarm shall be
generated by the BMS and the system shall automatically switch to the lag pump. A
pump sequencer shall be provided for both sets of primary pumps and the lead pump
designation shall be switched daily.
NOTE: All wiring between control components of boilers including but not limited to gas
train, boiler controller furnished by manufacturer and burner emergency switches shall be
wired and tested by the temperature control contractor.
3.09
COMBUSTION FAN SYSTEM
When water heater operation is requested, the BMS shall command the combustion fan
system to start. The fan shall modulate to maintain a constant positive static pressure in
the boiler room via linked space pressure sensor to the motor drive speed controller.
B.
3.10
An alarm shall be provided by the BMS if the combustion fan fails to operate.
GENERAL ALARM STATUS MONITORING
The equipment and panels listed below shall be monitored for general alarm. Upon
contact closure indicating an alarm condition, an alarm shall be activated at the control
panel.
3.11
1.
Water treatment system.
2.
Water/leak detection in the boiler room.
EXHAUST FANS
All Fans: BMS shall monitor the operation or failure (fan status) through a current
sensing relay switch. For fans with variable frequency drives (VFD), BMS shall monitor
fan status through an alarm output contact at the VFD. If fan has been signaled to start
and feedback from the relay or VFD does not indicate the fan has started after 30
seconds, fan shall be shut down and an alarm shall be activated at the central PC. If
damper end switches do not indicate respective dampers are open, fan shall be shut
down and an alarm shall be activated at the central PC. Conversely, if status is detected
while the fan is turned off or a damper is indicated open, a separate "Hand" alarm shall
be generated.
102313
PROJECT NO, BI-RT-844-CMR
SECTION 23 09 93
SEQUENCE OF OPERATION FOR HVAC CONTROLS
PAGE 10 OF 15
Temperature Controls: Upon a rise in space temperature above sensor setpoint,
associated motorized dampers shall open and respective fans shall staG.
Time of Day: Associated motorized dampers shall open and respective fans shall star
only during scheduled occupied modes.
Fans Controlled by Toggle Switches and Twist Type Timer Switches. Associated
motorized dampers shall open and respective fan(s) shall star only when switch is in the
"on" position. Operation shall also be subject to a Time of Day schedule.
Fans Served by a Differential Pressure Switch: If differential pressure is below setpoint,
an alarm shall be activated at the central PC.
LEF-1,2,3,4,5,6 and 7: Fans shall be interlocked with RTU-C1, C2, & C3. LEF-2 and 5
shall operate continuously. LEF-1,3,4,6,&7 shall be activated via a toggle switch on the
fume hood. The outside air dampers on RTU - C2 & C3 shall modulate to maintain a
building differential pressure. The TSI ain%w monitor shall provide a local alarm to the
user indicating the fan is inoperable.
KEF-I&2: Fans shall be interlocked with MAU-I&2. The recirculation damper on MAUl&2 shall close and the units operate on 100% outside air while KEF-1 &2 of enabled.
Fans shall be enabled via toggle switches mounted on the wall adjacent to the hoods.
H.
Dust Collector:
StaG-stop of the dust collector fan shall be controlled by a wall mounted switch
through the BMS. Operation shall be subject to a Time of Day schedule. If fan
has been signaled to stag and a damper end switch does not indicate a damper
is open after 30 seconds, unit shall be shut down and an alarm shall be activated
at the central PC. Conversely, if fan is signaled to be off and a damper is
indicated open, a separate "Hand" alarm shall be activated at the central PC.
BMS shall monitor a separate switch which shall control position of the dampers
at the discharge of the dust collector to exhaust the air or return the air back to
the space.
Dust collector shall be interlocked with ERV-S5. When dust collector is on and
dampers are switched to exhaust mode, ERV-S5 shall be on and shall provide
100% outside air.
3.12
3.13
ELEVATOR MACHINE ROOMS
A.
Connect and monitor existing equipment.
B.
On room temperature above 80 degrees F and stag exhaust fans.
C.
On room temperatures above 90 degrees F signal alarm.
EXCESS PRESSURE CONTROLS
Maintain constant pressure differential between supply and return lines by varying pump
speed through variable speed drive control.
102313
PROJECT NO, BI-RT-844-CMR
SECTION 23 09 93
SEQUENCE OF OPERATION FOR HVAC CONTROLS
PAGE 11 OF 15
3.14
RADIANT CEILING PANELS
Space temperature sensor shall maintain constant space temperature by modulating
two-way control valve in conjunction with the VAV box serving the zone.
3.15
RADIATION
Space temperature sensor shall maintain constant space temperature by modulating
two-way control valve.
3.16
TERMINAL AIR UNIT
A.
3.17
Refer to section 23 36 00.
MAKEUP AIR UNIT CONTROL
Unit shall be activated through a wall switch which also serves the respective exhaust
fan. When the unit is activated the supply fan shall operate continuously and the outside
air damper in unit shall be fully open.
Return air damper: Damper shall be open during the occupied cycle, except when the
respective KEF is operating.
Unit shutdown: Supply fan shall be de-energized and the outside air damper shall be
fully closed.
Freezestat: If the temperature at the outlet of the heating coil is below 40 degrees F, the
supply fan shall stop, the outside air damper shall close, the heating valve shall modulate
fully open and an alarm shall be activated.
Differential pressure switch: When the differential pressure across the filters exceeds 0.4
in wg, an alarm shall be activated.
When the supply fan is energized, "proof of fan running" shall be accomplished via air
flow switch or current transformer relays. If fan does not start or stops operating, an
alarm shall be activated.
Temperature Control: The BMS shall modulate the burners to maintain the space
temperature setpoint.
3.18
FAN COIL UNIT CONTROL
A.
Heating/Cooling Mode Change Over
Supply fan coil unit with heating/cooling thermostat which will automatically
change the unit from heating to cooling mode based on space temperature and
thermostat set point. Thermostat shall have separate heating and cooling set
points with an adjustable dead band.
B.
Heating/Cooling Mode Change Over
Supply fan coil unit with heating/cooling thermostat which will automatically
change the unit from heating to cooling mode based on space temperature and
thermostat set point. Thermostat shall have separate heating and cooling set
points with an adjustable dead bands.
102313
PROJECT NO, BI-RT-844-CMR
SECTION 23 09 93
SEQUENCE OF OPERATION FOR HVAC CONTROLS
PAGE 12 OF 15
Heating Mode
Upon a drop in space temperature below the field adjustable set point of 70
degrees F the unit shall be placed in heating mode. The control valve on the
heating coil shall be cycled opened and closed to maintain space temperature.
Cooling Mode
Upon a rise in space temperature above the field adjustable set point of 75
degrees F the unit shall be placed in cooling mode. The air cooled condenser
shall be staged to provide cooling.
Fan Control
1.
Unoccupied mode: During unoccupied periods the fan shall be deactivated.
Unoccupied mode: Upon a call for either heating or cooling the fan shall cycle
on. when the call for heating or cooling is satisfied the fan shall be deactivated.
3.
Occupied mode:
Option 1 : The fan coil unit's fan shall be interlocked with EF-1 such that
when EF-1 is activated the fan shall be activated and shall run
continuously at a constant speed.
Option 2: The fan coil unit's fan shall be interlocked with the lights such
that when the lights are on the fan shall be activated and shall run
continuously at a constant speed.
Option 3: The fan coil unit shall be supplied with an occupancy sensor.
The fan coil unit's fan shall be controlled by the occupancy sensor such
that when the room is occupied the fan shall run continuously at a
constant speed.
3.19
DUCT MOUNTED SMOKE DAMPERS
A.
3.20
Dampers shall be controlled by the fire alarm system. The BMS shall monitor the fire
alarm system for unit shutdown. Dampers shall close when the respective air handling
unit is shutdown or when smoke is detected at damper's respective duct mounted smoke
sensor. Fire alarm system shall be capable of remotely controlling position of damper
and have remote indication of position of damper.
DUCT MOUNTED HEATING COILS
A.
All Coils: Upon a drop in space temperature below sensor setpoint, heating mode shall
be activated. Respective control valve shall modulate to maintain supply air temperature
setpoint, reset by BMS.
Freezestat: If supply air temperature is below freezestat setpoint, respective hot water
coil shall be fully open, respective supply fan shall stop and an alarm shall be activated at
the central PC. Freezestat shall be active when respective unit is in occupied and
unoccupied modes.
102313
PROJECT NO, BI-RT-844-CMR
SECTION 23 09 93
SEQUENCE OF OPERATION FOR HVAC CONTROLS
PAGE 13 OF 15
3.21
FUEL OIL SYSTEM (at HVAC shop)
Leak Detection: Monitor the local leak detection system for leaks in both the above
ground oil storage tank interstitial space and the underground piping. Any leak shall
create an alarm condition and shall shut the fuel oil pump set off.
Pump Set and Day Tank: Provide oil sensors in the pans for both the fuel oil pump set
and the day tank. Monitor both oil sensors. Upon sensing of oil in either pan, oil pump set
shall shut off and an alarm condition shall be created.
3.22
SUMP PUMPS SP-1 &SP-3
Monitor the local pump controller for lag pump operation. When the lag pump operates
an alarm condition shall be created.
3.23
GENERAL DEVICES
Variable Frequency Drives: BMS shall control start/stop of each VFD and shall monitor a
general alarm contact at the VFD. If the VFD is in alarm mode, an alarm shall be
activated at the central PC. BMS shall control speed of each VFD.
Alarm Contacts: BMS shall monitor alarm contacts as shown on the drawings. If a
device is in alarm mode, an alarm shall be activated at the central PC.
Water Heater Combustion Air: When the burner contact is engaged, the respective
combustion air intake dampers shall open. If dampers have been signaled to open and a
damper end switch does not indicate a damper is open after 30 seconds, the water
heater shall be de-activated and an alarm shall be activated at the central PC.
Conversely, if water heater is indicated as off and a damper is indicated open, a separate
"Hand" alarm shall be activated at the central PC.
Domestic Hot Water Recirculating Pumps: Pumps shall be controlled per a time of day
schedule and shall be activated during occupied modes.
Carbon Monoxide Sensors: BMS shall monitor panel and display alarms. If CO levels
rise above setpoint, respective exhaust fan(s) shall start and heating and ventilating units
shall start and provide 100% outside air. At the boiler room, boilers and water heater
shall be shut down.
3.24
OUTDOOR AIR CONDITIONS MONITORING
A.
Functional Control
The controller will read the outside air temperature and enthalpy and calculate
the outside air enthalpy, and will make these values available to the system.
If the outside air temperature sensor indicates a reading lower than -25°F with a
hysteresis of 10 or higher than 225°F with a hysteresis of 10 the controller will
make the alternate outside air temperature sensor available to the system. Ifthe
sensor still indicates these readings after 5 minutes, the controller will generate a
sensor failure alarm.
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PROJECT NO, BI-RT-844-CMR
SECTION 23 09 93
SEQUENCE OF OPERATION FOR HVAC CONTROLS
PAGE 14 OF 15
B.
Temperature History
Once the controller has established communication with the system after any
interruption in communication, it will record a temperature history for the system.
At 12:05 am every night, the controller will reset the high and low daily
temperature peak recorders for the next day. The reset signal will last
no longer than 5 seconds.
When the high and low daily temperature peak recorders are reset for
the first day of each month, the high and low month-to-date peak
recorders will also be reset.
When the high and low month-to-date peak recorders are reset for
January, the high and low year-to-date peak recorders will also be reset.
3.25
ALARM NOTIFICATION
Events and alarms shall be indicated on the appropriate equipment graphics page
viewable and with automatic display updates available at the central server level. The
graphic display will indicate an alarm condition by showing the appropriate object in red
on the graphic display.
Alarms and events shall be displayed on the Event Log Page viewable and with
automatic display updates available at the central server level. Date and time of
occurrence shall be recorded.
Alarms and events shall be transferred out of the automation system to other network
services for remote notification to: printers on the customer's network, e-mail system,
local sounds, or other reporting actions, depending on user configuration.
3.26
TRENDING
All I/O points will be linked to a trend log and additional trends will be provided as shown
in the tables below.
The controller will be able to record a trend sample every 10 minutes on each of
the trend objects.
The controller will save the most recent 144 samples of each trended point in the
control module for viewing or printing.
The user will be able to enable or disable trending of any of the points listed.
Points marked with an asterisk will automatically be trended in the default
configuration.
For the first year of operation, the system will trend and record all data at 10
minute increments which can then be backed up on CD's.
3.27
COMMISSIONING
Engage a factory-authorized service representative, to perform sta•tup service as per
functional test sheets and requirements of Section 23 08 00 Commissioning.
Verify that equipment is installed and commissioned as per requirements of Section 23
08 00 and manufacturer's written instructions.
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PROJECT NO, BI-RT-844-CMR
SECTION 23 09 93
SEQUENCE OF OPERATION FOR HVAC CONTROLS
PAGE 15 OF 15
Complete installation and startup checks and functional tests according to Section 23 08
00 and manufacturer's written instructions.
Operational Test: After electrical and control systems have been energized, start units to
confirm proper unit operation. Rectify malfunctions, replace defective parts with new one
and repeat the start up procedure.
Test and adjust controls and safety devices. Replace damaged and malfunctioning
controls and equipment.
END OF SECTION
102313
PROJECT NO. BI-RT-844-CMR