McQuay WSC Operating Manual page 41

Alarms fall into three distinct categories: Faults, Problems, and Warnings as detailed in the following
section.
Fault Alarms
The following table identifies each fault alarm, its display, gives the condition that causes the alarm to
occur, and states the action taken because of the alarm. All fault alarms require a manual reset and trigger
the remote alarm signal.
Table 20, Fault Alarm Description
Description
Low Evaporator Pressure
High Condenser Pressure
Vanes Open No Start
Low Oil Delta Pressure
Low Oil Feed Temperature
High Oil Feed Temperature
Low Motor Current
High Discharge Temperature
Mechanical High Pressure
High Motor Temperature
Surge Temp High
Surge Temp Slope High
Compressor Surge Eminent
No Starter Transition
No Compressor Stop
Starter Fault
Low Oil Pressure Start
No Evaporator Water Flow
No Condenser Water Flow
Leaving Evaporator Water
Temperature Sensor Fault
Evaporator Pressure Sensor
Fault
Condenser Pressure Sensor
Fault
Suction Temperature Sensor
Fault
Discharge Temperature
Sensor Fault
Oil Feed Temperature
Sensor Fault
Oil Sump Temperature
Sensor Fault
Oil Feed Pressure Sensor
Fault
Oil Sump Pressure Sensor
Fault
NOTES:
1.
Surge Temperature is defined as the suction temperature minus the leaving chilled water temperature.
2.
Delta-P switch used only on chillers manufactured in Europe.
3.
Starter alarm faults will be sent from the starter and will also appear here. They are discussed elsewhere in this manual.
OM Centrif Micro ΙΙ-5
Display
Evap Pressure Low Evaporator Press < Low Evap Pressure SP
Condenser Press High Cond Press > High Condenser Pressure SP
Vanes Open
(Comp State=PRELUBE, RUN, UNLOAD, or
Oil Delta Pressure Low
Oil Feed Temp Low
(Evap Saturated Refr Temp + Low Oil Delta
Oil Feed Temp High
I < Motor Current Threshold with Compressor
Motor Current Low
Disch Temp High
Mechanical High Press
High Motor Temp
Surge Temperature
Note 1
Surge Temp Slope > Surge High Slope SP
Surge Switch
Note 2
Starter Transition Digital Input = No Transition
No Starter Transition
Current High with %RLA > Motor Current Threshold SP with
Comp Off
Starter Fault
Oil Pressure Low-Start
Evaporator Water Flow
Loss
Condenser Water Flow
Loss
Evap LWT Sensor Out
of Range
Evap Pressure Sensor
Out of Range
Cond Pressure Sensor
Out of Range
Suction Pressure
Sensor Out of Range
Discharge Temp Sensor
Out of Range
Oil Feed Temp Sensor
Out of Range
Oil Sump Temp Sensor
Out of Range
Oil Feed Pressure
Sensor Out of Range
Oil Sump Pressure
Sensor Out of Range
Occurs When:
Compressor state = PRELUBE for 30 sec
after Prelube timer expires
POSTLUBE)
& Net Oil Press < Low Net Oil Press SP
(Comp State=RUN or UNLOAD) &
Oil Feed temp <
Temperature SP) for > 1 min
Temp > High Oil Feed Temperature SP
ON for 30 sec
Temp > High Discharge Temperature SP
Digital Input = High Pressure
Digital Input = High Temperature
Surge Temp > Surge Temp SP
Delta-P Switch Senses Reverse Pressure
Across the Discharge Check Valve
AND Compressor ON for > 15 seconds
Compressor OFF for 30 sec
Starter Fault Digital Input = Fault AND
Compressor State = START, PRELUBE,
RUN, or UNLOAD
Compressor State = START for 30 sec
Chilled Water Flow Switch Open
Condenser Water Flow Switch Open
Sensor shorted or open
Sensor shorted or open
Sensor shorted or open
Sensor shorted or open
Sensor shorted or open
Sensor shorted or open
Sensor shorted or open
Sensor shorted or open
Sensor shorted or open
Action Taken
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Annunciation
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
Rapid Stop
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