Greenheck MPX (472695) User Manual
Page 17
Building Freeze Protection
If the supply air temperature drops below 35°F
(adjustable), the DDC will de-energize the unit and
activate the alarm output after a preset time delay.
Alarms Indication
The DDC has a single digital output for remote
indication of an alarm condition. Possible alarms
include:
• Dirty Filter Alarm
If the outside air or return air filter differential
pressure rises above the switch set point
(adjustable), the differential pressure switch
signals the DDC to activate the alarm.
• Supply Air Alarm
The DDC monitors the proving switch on the
supply air blower and displays an alarm in case of
blower failure.
• DX Alarm
The DDC monitors the refrigerant pressure and
shuts off the refrigeration circuit in the case of
high or low refrigerant pressure.
• Temperature Sensor Alarm
The DDC will send an alarm in the case of a failed
air temperature sensor.
BMS Interfacing
A BMS serial card is provided with the DDC controller
for field interfacing with a Building Management
System (BMS). Each card is sent out with the default
parameters and the controls contractor must change
the appropriate addresses to match the BMS settings.
See also the detailed instructions provided by the
DDC manufacturer.
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Model MPX Make-Up Air Unit
®