Instruction manual

28 McQuay OM 920
Keypad/Display Menu Structure
Dehumidification Menu
Dehum Status is a status only item that indicates whether dehumidification is enabled or
disabled.
Rel Humidity is a status only item that indicates the current relative humidity reading of the
sensor.
DewPoint is a status only item that indicates the current value that is calculated by the
controller using the Rel Humidity value and either the Space Temp or Return Air value,
depending on the setting of the Humidity Sensor Location. This parameter can either be set to
“Space” or “Return.”
Dehum Method is an adjustable item used to set the dehumidification method to either “RH”
or “DewPt.” When this parameter is set to “RH,” dehumidification operation is controlled to
maintain the Rel Humidity value at the Relative Humidity Set Point. When this parameter is
set to “DewPt,” dehumidification operation is controlled to maintain the Dew Point= value at
the Dew Point Set Point.
RH Setpoint is an adjustable item used to set the relative humidity value at which the relative
humidity will be controlled to during dehumidification operation.
Dewpoint Spt is an adjustable item used to set the Dewpoint value at which the dewpoint with
will be controlled to during dehumidification operation.
Reheat Spt is a status only item which is used to indicate the DAT temperature to which the
HGRH valve will be controlled to in the Cooling and Fan Only operating states while
dehumidification operation is active. The Reheat Setpoint equals the DAT Cooling Setpoint
for DAT controlled units and will vary in between the minimum and maximum reheat setpoint
for Zone Controlled units.
Reheat Cap is a status only item that indicates the current reheat capacity value.
Daily Schedule Menu
The Daily Schedule sets the start and stop times for each of the days of the week. One start and
one stop time can be set for each day.
Table 17: Dehumidification Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Dehumidification Dehum Status= - Disabled 6
Enabled
Rel Humidity= - 0-100% 6
Dewpoint= - -50-150°F 6
Dehum Method= None None 6
Rel Hum
DewPt
RH Setpoint= 50% 0-100% 6
Dewpoint Spt= 50°F 0-100°F 6
Reheat Spt= - 40.0-100.0°F 6
Reheat Cap = - 0-100% 6
Table 18: Daily Schedule Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Daily Schedule Mon= 00:00 – 00:00 00:00 – 23:59 6
Tue= 00:00 – 00:00 00:00 – 23:59 6
Wed= 00:00 – 00:00 00:00 – 23:59 6
Thu= 00:00 – 00:00 00:00 – 23:59 6
Fri= 00:00 – 00:00 00:00 – 23:59 6
Sat= 00:00 – 00:00 00:00 – 23:59 6
Sun= 00:00 – 00:00 00:00 – 23:59 6
Hol= 00:00 – 00:00 00:00 – 23:59 6