Data Aire gForce Ultra - Relative Humidity Control Mode

10-2014 gForce User Manual ● 113
 If dehumidification is programmed for “1C in Limit” or “2C in Limit” the
dehumidification cooling will be inhibited by reheat if the return air temperature
drops below Temperature Setpoint - Temperature DB - 2⁰F. Dehumidification
will be inhibited until the return air temperature rises above the Temperature
Setpoint. Compressor short-cycle time will not be violated.
 If dehumidification is programmed for “1C No Limit” or “2C No Limit”,
dehumidification remains on until the humidity setpoint is reached. In this mode,
dehumidification has priority and overcooling is disregarded. The reheat
sequence will remain the same.
 There is a one (1) minute delay between stop-to-start of dehumidification
cooling. Compressor short-cycle time delay will not be violated.
 There is a five (5) minute delay between dehumidification and humidification.
 Relative humidity control mode is not recommended for Discharge Temperature
Control, Dewpoint Control method should be used in this case.
 The compressor staging sequence for dehumidification cooling is as follows:
9.4.1 Relative Humidity Control Mode
9.4.1.1 Single Variable Speed Compressor System
Dehumidification cycles on
 If the unit is not in cooling mode, the variable speed compressor turns on when
humidity is at Humidity Setpoint (HSP) + Humidity Deadband (HDB).
o The compressor will modulate speed from 0% to 100% in 1% RH above
Humidity Setpoint + Humidity DB. For instance:
o If Humidity = Humidity Setpoint + Hum Deadband, VFD will run at 0VDC
o If Humidity = Humidity Setpoint + Hum Deadband + 0.1%, VFD will run at
10%
o If Humidity = Humidity Setpoint + Hum Deadband + 0.2%, VFD will run at
20%, etc.
 If cooling required during dehumidification cycle and dehumidification mode is
set to “1C in Limit” the temperature cooling control will override the
dehumidification cooling control. If dehumidification mode is set to “1C No
Limit”, the unit will continue to finish the dehumidification cycle then switch to
Temperature Control Cooling Mode.
Dehumidification cycles off