Instruction manual

22 McQuay OM 920
Keypad/Display Menu Structure
Evap Condensing Menu
Cond Fan Speed is a status only item that displays the current VFD speed when the
evaporative condenser option includes a VFD to control the first condenser fan on each circuit.
Cond Fan Spd Cmd is a status only item that indicates the current Condenser fan VFD
commanded speed.
Min Fan Speed is an adjustable item used to set the minimum speed for the VFD speed when
the evaporative condenser option includes a VFD to control the first condenser fan on each
circuit.
Stage Time is an adjustable item used to set a minimum time period between condenser fan
stage changes.
Sump Temp is a status only item that displays the current evaporative condenser sump
temperature.
Min Sump T is an adjustable item used to set a minimum evaporative condenser sump
temperature set point. This value is used to determine when condenser fans are turned off.
Max Sump T is an adjustable item used to set a maximum evaporative condenser sump
temperature set point. This value is used to determine when condenser fans should be turned
on.
Sump Dump Spt is an adjustable item used to set a minimum sump temperature. The sump is
emptied to prevent freezing if the sump temperature drops below this set point.
Sump Pump Status is a status only item that displays the current evaporative condenser sump
pump status.
Smp Pmp Delay adjustable item used to set the amount of time the sump pump fail alarm is
delayed. If the Sump Pump status remains Off after the Sump Pump Output has been turned on
for more than the Sump Pump Delay time, a Sump Pump fail alarm is initiated.
Conductivity is a status only item that displays the conductivity level of the water in the sump
of an evaporative cooled condenser on rooftop units.
Dolphin System is an adjustable parameter that indicates to the controller whether or not a
Dolphin water treatment method is being used. When set to “yes” the controller assures the
sump pump is run every three days to reduce scaling.
Table 12: Evap Condensing Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Evap Condensing Cond Fan Spd= - 0-100% 6
CFan Spd Cmd= - 0-100% 6
Min Fan Speed= 25% 0-100% 6
Stage Time= 10min 0-100min 6
Sump Temp= - -50.0-150.0°F 6
Min Sump T= 75.0°F 0.0-100.0°F 6
Max Sump T= 85.0°F 0.0-100.0°F 6
Sump Dump Spt= 3-5.0°F 0.0-100.0°F 6
Pump Status= - Off 6
On
Smp Pmp Delay= 30s 0-300s 6
Conductivity= - 0-5000S/cm 6
Dophin System= No No 6
Yes