Discharge Air Temperature; High Discharge Air Temp; Low Discharge Air Temp; Discharge Air Sensor Failure - FHP 641-224 User Manual

The controller will only allow supplemental heating if the unit is configured to allow this
operation, units equipped with hot gas re heat valves or damper control enable will not have
supplemental electric heat functionality.

Discharge Air Temperature:

The controller will monitor the discharge air temperature to be located at discharge side of coil. If
the supplemental heating is installed then sensor will be in the discharge side of heating coil.
Alarms will be provided as follows:
High Discharge Air Temp: If unit running in cool mode and the discharge air temperature is
greater than 70°F (adj.).
Low Discharge Air Temp: If unit running in heat mode and the discharge air temperature is
less than 75°F (adj.).
Discharge Air Sensor Failure: If discharge air sensor outside of normal operating limits.

Discharge Air Control

On units with factory mounted modulating re-heat valves the controller will operate the unit to
maintain a particular discharge temperature setpoint. The discharge air temperature sensor
(DATS) will be located at discharge side of coil preferable 3/4 downstream of the total length of
the duct work.
The controller can operate on single or Multiple Outside Air Temperature Reset, the controller
will monitor the value of the Outside Air temperature via a BACnet point or via a physical point
terminated in one of the controllers available inputs. The controller will stage the unit's
compressors and modulate the re-heat valve mode to maintain the Discharge Air Setpoint (User
adjustable).
Two modes are selectable for Discharge Air Control (DAC) Applications are as follows:
 Single Outside Air Temperature Reset point
 Multiple Outside Air Temperature Reset points
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