Instruction manual

50 McQuay OM 920
Keypad/Display Menu Structure
* Max Heat Rise represents positions 12, 13 and 14 of the Software Configuration Code.
Save/Restore Menu
The Save/Restore menu can be used to save or restore the user configured parameters as well
as reset the controller back to the factory default parameters.
Alarm Delays Setup Menu
The Alarm Delays Setup Menu can be accessed when a level 2 password has been entered.
The default settings are the result of many years of testing and should not be changed.
The Alarm Delay Setup Menu should only be accessed by trained service personnel.
17 Return/Exhaust Fan
Capacity Control
Method
0 = None •
1 = Tracking
2 = Building Pressure
3 = Position
18 Second Duct
Pressure Sensor
0 = No • •
1 = Yes
19 Entering Fan Temp
Sensor
0 = No •
1 = Yes
20 Energy Recovery 0 = None •
1=ConstSpdWhl
2=VarSpdWhl/Grhm
3=VarSpdWhl/McQ21
21 Cooling Circuit Type 0 = Individual • •
1 = Dual Circ. Water Condenser
2 = Dual Circ. Air Condenser
22 Head Pressure
Control
0 = No •
1 = Yes
23 Bypass Valve Control 0 = Slave •
1 = Bypass
24, 25, 26 Unit Size Three digits
(default 050) ••
27 Refrigerant Type 0 = R22 • •
1 = R407C
2 = R410A
28 HGRH Type 0 = None •
1 = Staged
2 = Modulating
Table 44: Save/Restore Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Save/Restore Save Params= No No/Yes 2
Rstr Params= No No/Yes 2
Rstr Factory= No No/Yes 2
Table 45: Alarm Delays Setup Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Alarm Delays OffHtClDelay= 120s 0-999s 2
Frz DelayTime= 30s 0-180s 2
LP Delay= 2s 0-10s 2
LP Comp Delay= 65s 0-300s 2
Aflw Ignr Tm= 120s 0-999s 2
Sens Alm Dly= 30s 0-300s 2
Temp Alm Dly= 30s 0-300s 2
Table 43: Unit Configuration Menu
Configuration
Code Position
Description Values (Default Bold) RTU SCU