Instruction manual

McQuay OM 920 41
Keypad/Display Menu Structure
Dehumidification Setup Menu
RH DB is an adjustable item that sets a dead band around the relative humidity set point. For
example, if the RH Setpoint parameter is set to 50% and the RH Db parameter is set to 2% the
dead band around the set point would be from 49% to 51%.
Dewpoint DB is an adjustable item that sets a dead band around the dew point set point. For
example, if the DewPoint Spt parameter is set to 50ºF and the DewPntDb parameter is set to
2ºF the dead band around the set point would be from 49ºF to 51ºF.
Dehum Method is an adjustable item used to select whether dehumidification operation is
based on relative humidity or dew point.
Dehum Ctrl is an adjustable item used to select whether dehumidification as “always”
allowed or only during “occupied” modes of operation.
Sensor Loc is an adjustable item which is used to select the location of the humidity sensor.
The location is selected by setting the Sensor Location value on the keypad to Return, Space,
or OAT. The significance of the sensor location is that this determines which temperature
sensor is use to calculate the Dewpoint. OAT can only be selected for units with DAT control.
Table 36: Dehumidification Setup Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Dehum Setup RH DB= 2% 0-10% 4
Dewpoint DB= 2°F 2-10°F 4
Reheat Period= 10s 0-999s 4
Reheat Gain= 1 0.0-100.0 4
Reheat PAT= 20s 0-999s 4
RH Max Chg= 16% 0-100% 4
RH Stg Time= 10 0-60m 4
Dehum Method= None None 4
Rel Hum
DewPt
Dehum Ctrl= Occupied Occupied 4
Always
Sensor Loc= Return Return 4
Space
OAT
Mn Lvg Coil T= 48.0°F 4
Mx Lvg Coil T= 55.0°F 4
Min Rheat Spt= 55.0°F 40.0-100.0°F 4
Max Rheat Spt = 65.0°F 40.0-100.0°F 4
RH Sens Type= VDC VDC 4
mA
RH Min Signal= 0.0V 0.0-20.0 4
V/mA
RH Max Signal= 10.0V 0.0-20.0 4
V/mA