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ALM-231
Prestart Failure -
High Motor
Temperature
Manual
Unit shuts down.
Alarm relay turns on.
Check Comp Motor Wind Temp in Temperature screen.
Check motor temperature sensor for wiring and accuracy to IOB
connector.
Check motor cooling line and isolation valves for proper operation, or
restrictions, check refrigerant filter/drier.
Check for excessive starts within a short time span.
Check Comp Motor Temp Override setting.
ALM-232
Prestart Failure -
High Discharge
Temp
Manual
Unit shuts down.
Alarm relay turns on.
Check Comp Discharge Temp in screen
Allow compressor discharge temperature sensor to cool.
Check compressor discharge temperature sensor wiring and accuracy
to IOB connector.
Check for excessive starts.
Check COMP DISCHARGE ALERT setting.
ALM-233
Prestart Failure -
Low Refrigerant
Temp
Manual
Unit shuts down.
Alarm relay turns on.
Check Evaporator Pressure, Evap Sat Refrig Temp, and Evap Refrig
Liquid Temp.
Check REFRIG OVERRIDE DELTA T and EVAP REFRIG TRIPPOINT
in configuration screen.
Check refrigerant charge.
Check for low chilled water supply temperatures.
Check Evaporator Pressure transducer and Evaporator Refrigerant
Liquid Temperature sensor wiring and accuracy.
ALM-234
Prestart Failure -
Low Line Voltage Manual
Unit shuts down.
Alarm relay turns on.
Check ACTUAL LINE VOLTAGE.
Check UNDERVOLTAGE THRESHOLD in ISM_CONF screen.
Check voltage supply.
Check wiring to ISM J3-L1, J3-L2, and J3-L3.
Check voltage transformers and switch gear.
Consult power utility if voltage is low.
ALM-235
Prestart Failure -
High Line
Voltage
Manual
Unit shuts down.
Alarm relay turns on.
Check ACTUAL LINE VOLTAGE.
Check OVERVOLTAGE THRESHOLD in ISM_CONF screen.
Check voltage supply.
Check voltage transformers and switch gear.
Consult power utility if voltage is high.
ALM-236
Guide Vane 1
Calibration Not
Completed
Manual
Unit shuts down.
Alarm relay turns on.
Guide Vane 1 Calibration in Quick Calibration screen.
Check guide vane actuator feedback potentiometer and wiring to IOB
connector.
ALM-237
Prestart Failure –
No Power Supply Manual
Unit shuts down.
Alarm relay turns on. Check the Power Request Output and the Power Feedback input status.
ALM-238
Guide Vane 2
Calibration Not
Completed
Manual
Unit shuts down.
Alarm relay turns on.
Guide Vane 2 Calibration in Quick Calibration screen.
Check guide vane actuator feedback potentiometer and wiring to IOB
connector.
ALM-239
Envelope Control
Valve Calibration
Not Completed
Manual
Unit shuts down.
Alarm relay turns on.
Envelope control valve Calibration in Quick Calibration screen.
Check EC valve feedback potentiometer and wiring to IOB connector.
ALM-240
Damper Valve
Calibration Not
Completed
Manual
Unit shuts down.
Alarm relay turns on.
Tested on control test mode or prestart check, if Damper calibration is
failed.
ALM-250
Protective Limit -
Oil Pressure
Difference
Failure
Manual
Unit shuts down.
Alarm relay turns on.
Check oil pump
Check oil filter
Check oil pump wiring
ALM-251
Protective Limit -
Low Chilled
Water Flow
Manual
Unit shuts down.
Alarm relay turns on.
Perform Chilled Water pump test in Quick Test screen. Check Evap
Refrig Liquid Temp and Leaving CHILLED WATER temperature sensor
accuracy and wiring to IOB.
Check chilled water valves, pumps, and strainers.
Check EVAP REFRIG TRIPPOINT, EVAP APPROACH ALERT, EVAP
FLOW DELTA P CUTOUT, and WATER FLOW VERIFY TIME settings.
Check load resistors, optional water flow switches or water flow delta P
transducer calibration and wiring to IOB.
Check for 5.0 V reference voltage between IOB connectors.
ALM-252
Protective Limit -
Low Condenser
Water Flow
Manual
Unit shuts down.
Alarm relay turns on.
Perform Condenser Water pump test in Quick Test screen. Check
CONDENSER PRESSURE transducer and LEAVING CONDENSER
WATER temperature sensor accuracy and wiring.
Check condenser water valves and strainers. Check COND PRESS
OVERRIDE, COND APPROACH ALERT, COND FLOW DELTA P
CUTOUT, and WATER FLOW VERIFY TIME settings.
Check load resistors, optional water flow switches or water flow delta P
transducer calibration and wiring to IOB. Check for 5.0 V reference
voltage between IOB connectors.
ALM-253
Protective Limit -
High Discharge
Temp
Manual
Unit shuts down.
Alarm relay turns on.
Check for closed compressor discharge isolation valve.
Check if chiller was operating in surge conditions.
Check COMP DISCHARGE TEMP sensor resistance or voltage drop.
Check for proper wiring to IOB connectors.
Check for proper condenser flow and temperature.
Check for fouled tubes, plugged water strainers, or non-condensable in
the condenser.
Check for COMP DISCHARGE TEMP > 220 deg F.
Check for proper inlet guide vane and optional diffuser actuator
operation.
Table 16 — PIC6 Alarm Codes* (cont)
ALARM CODE
DESCRIPTION
OF ALARM TEXT
RESET TYPE
ACTION TAKEN BY
THE CONTROL
POSSIBLE CAUSE