Instruction manual

McQuay OM 920 21
Keypad/Display Menu Structure
Max Clg Spt = 65.0 F
Max Clg Spt @ = 35%
Based on the above, the unit will have a discharge air temperature setpoint of 55.0 F from 80%
to 100% of the airflow.
Figure 5: Cooling Setpoint
Head Pressure Menu
The Head Pressure menu contains parameters that are used to maintain head pressure control.
WRV Pos is a status only item that indicates the current water regulating valve position.
Head P Circ 1 is a status only item that indicates the current refrigerant pressure for circuit
#1.
Head P Circ 2 is a status only item that indicates the current refrigerant pressure for circuit
#2.
Setpoint is an adjustable item that sets the refrigerant setpoint used for controlling the water
regulating valve. The water-regulating valve is modulated to maintain the refrigerant pressure.
Note – This section only applies to Self Contained units with a water regulating valve.
Table 11: Head Pressure Menu
Menu Display Name Item Display Name Default Setting Range Password Level
Head Pressure WRV Pos= - 0-100% 6
Head P Circ 1= - 0-750psi 6
Head P Circ 2= - 0-750psi 6
Setpoint= 260psi 230-340psi 6