FHP AHP 641-224, User Manual

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Controller will command the unit to run full mechanical cooling operation (on units with more
than two compressors please check with factory), the valve will be set for cooling operation and
both first and second compressors will be commanded on, the fan will run continuously or if the
unit is equipped with a Variable Frequency Drive (VFD) it will command the drive to maintain its
static pressure setpoint and the re-heat valve will be modulated to maintain a 65°F (Factory
Default (adj.)) discharge air temperature setpoint .
Leaving Water Temperature:
The controller will monitor the leaving water temperature.
Alarms will be provided as follows:
High Leaving Water Temp:
If compressor(s) is running and the leaving water temperature is
greater than 135°F (adj.).
Low Leaving Water Temp:
If compressor(s) is running and the leaving water temperature is
less than 35°F (adj.).
Leaving Water Sensor Failure:
If leaving water sensor outside of normal operating limits.
Should a High or Low Leaving Water Temperature Alarm occur, the call for heat or cool will be
removed.
UPM Fault Monitor:
The controller will monitor the Unit protection Module (UPM) fault input.
Upon hard lock out alarm, compressors are disabled by FHP UPM board.
Alarms will be provided as follows:
HP1: High Pressure Alarm (circuit 1)
HP2: High Pressure Alarm (circuit 2)
LP1: Low Pressure Alarm (circuit 1)
LP2: Low Pressure Alarm (circuit 2)
FRE: Freeze Alarm
CON: Condensate Alarm
BRN: Brownout Alarm