SUPPLY FAN SEQUENCE
The factory installed BLDC Inverter PCB is wired to the
controller.
Supply fan speed needs to be set during test and
balance of the unit. The following sequences are
selectable for supply fan control. The fan speed in
constrained by its min and max speed set points.
Constant Volume:
Supply fan operates at a
constant speed, based on a constant volume set
point (%).
Air volume (CFM) Control:
The controller will
modulates fan motor speed to maintain designed air
flow rate even the total pressure is changed.
Optional Space CO2 Sensor:
The controller will
modulate the supply fan speed based upon a
comparison of the CO2 set point to the actual CO2
levels reported from the sensor.
EXHAUST FAN SEQUENCE
(if equipped)
The factory installed BLDC Inverter PCB is wired to the
controller.
Exhaust fan speed needs to be set during test and
balance of the unit. The following sequences are
selectable for supply fan control. The fan speed in
constrained by its min and max speed set points
Constant Volume:
Exhaust fan operates at a
constant speed based on a constant volume set
point (%) based on occupancy.
Air volume (CFM) Control:
The controller will
modulates fan motor speed to maintain designed air
flow rate even the total pressure is changed. If
Differential sensor equipped, at Exhaust fan section)
Supply Fan Tracking:
The exhaust fan
proportionally modulates based on the supply fan
speed plus an adjustable offset.
OUTDOOR AIR AND RECIRCULATED AIR
DAMPER SEQUENCE
(if equipped)
If equipped with a modulating outdoor air and
recirculated air damper, the recirculated air damper will
operate inverse of the outdoor air damper. The outdoor
air damper will open to a Minimum Outdoor Air Position
(Min OA) when in occupied mode. If equipped with BMS
communications, the user can also directly reset the
damper position up to the maximum OA position.
ENERGY RECOVERY WHEEL SEQEUNCE
(if
equipped)
Economizer:
The economizer will stop the energy
wheel to achieve free cooling.
Frost Control:
The microprocessor controller will
activate the frost control method when maintain
below conditions over 5 minutes
-
The outside air temperature is less than 32°F
-
The exhaust air temperature is less than 35.6°F.
Once the Exhaust air temperature increases over 45°F,
and maintain the condition for 1 minute, unit will resume
normal operation.
ALARMS
The microprocessor controller includes indication of an
alarm condition. Possible alarms include:
Main Module Communication Error (Fieldbus
Communication Alarm):
It occurs when
communication between the controller and the Main
Module is not established
.
DOAS Device Error (Device Error):
It occurs
when DOAS Device Error Code is sent from the
main module. Refer the DOAS Error Code Table (e.g
Filters, Sensors, Fan Motor etc.)
Note:
The alarm below is related with CAREL controller when
below alarms occurred it will be cleared after alarm
reset.
Retain Memory Alarm (Al_retain):
It occurs
when too many writes are made to the controller
Retain Memory
Retain Memory Write Error Alarm
(Al_Err_retain_write):
It occurs when a write
error occurs in the controller Retain Memory.
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