OMM 1130-2 29
High Condenser Pressure - Unload
Event description (as shown on screen): CondPressHighUnloadN
Trigger:
This event is triggered if all of the following are true:
• circuit state = Run
• more than one compressor is running on the circuit
• condenser pressure > High Condenser Pressure – Unload set point
Action Taken: Stage off one compressor on the circuit every 10 seconds, except the last one.
Reset: While still running, the event will be reset if condenser pressure drops below the “Hold Clear @”
value which is displayed on that circuit’s VIEW CIRCUIT n (1) screen. The “Hold Clear @” is calculated
based on number of compressors, refrigerant, and number of High Condenser Pressure – Unload
occurrences since the circuit has cycled off or since midnight. See table below:
Condenser
Configuration
Compressors R410A
R22
R407C
R134a
Step
Increase
Water-Cooled
4 40 psi 30 psi 30 psi 10 psi
6 30 psi N/A 20 psi 10 psi
Air-Cooled
4 100 psi 70 psi N/A 15 psi
6 80 psi N/A N/A 15psi
Failed Pumpdown
Event description (as shown on screen): Pumpdown Fail Cir N
Trigger: Circuit state = pumpdown for time > 60 seconds
Action Taken: Shutdown circuit
Reset: N/A
Condenser Freeze Event
Event description (as shown on screen): Cond Freeze Circ N
Trigger: Cond Sat Refr Temperatre < Condenser Freeze Set Point AND Condenser Pump State = OFF
Action Taken: Start condense pump.
Reset: N/A
Condenser Freeze Event (Water Cooled = Y Only)
Event description (as shown on screen): Cond Freeze Circ N
Trigger: Cond Sat Refr Temp < Condenser Freeze Set Point AND Condenser Pump State = OFF
Action Taken: Start condenser pump.
Reset: Cond Sat Refr Temp > Condenser Freeze Set Point plus 2°F.
Suction Temperature Sensor Fail
Event description (as shown on screen): SuctT Sensor Fail N
Trigger: Sensor shorted or open.
Action Taken: None.
Reset: N/A
Entering Evaporator Water Temperature Sensor Fail (TGZ unit only)
Event description (as shown on screen): Evap EWT Sensor Fail
Trigger: Sensor shorted or open.
Action Taken: None.
Reset: N/A
To Next Page
