Carrier PIC 5+ - Page 37

37


 



Alm-233 ALM-233 Prestart Failure - Low
Refrigerant Temp
As above As above Check Evaporator Pressure, Evap Sat Rreg Temp, and Evap Rreg
Liquid Temp.
Check Evaporator Pressure transducer and Evaporator Refrigerant
Liquid Temperature sensor wiring and accuracy.
Check for low chilled water supply temperatures.
Check refrigerant charge.
Check REFRIG OVERRIDE DELTA T and EVAP REFRIG TRIPPOINT
in conguration screen.
Alm-234 ALM-234 Prestart Failure - Low
Line Voltage
As above As above 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 ALM-235 Prestart Failure - High
Line Voltage
As above As above 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 ALM-236 Guide Vane 1
Calibration Not Completed
As above As above Guide Vane 1 Calibration in Quick Calibration screen.
Check guide vane actuator feedback potentiometer and wiring to IOB
connector.
Alm-237 ALM-234 Prestart Failure – No
Power Supply
As above As above Check the Power Request Output and the Power Feedback input
status.
Alm-238 ALM-238 Guide Vane 2
Calibration Not Completed
As above As above Guide Vane 2 Calibration in Quick Calibration screen.
Check guide vane actuator feedback potentiometer and wiring to IOB
connector.
Alm-239
ALM-239 Envelope Control
Valve Calibration Not Completed
As above As above Envelope control valve Calibration in Quick Calibration screen.
Check EC valve feedback potentiometer and wiring to IOB connector.

Alm-250 ALM-250 Protective Limit - Oil
Pressure Dierence Failure
Manual Unit shuts down. Check oil pump
Check oil lter
Check oil pump wiring
Alm-251 ALM-251 Protective Limit - Low
Chilled Water Flow
As above As above 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 ow switches or water ow delta
P transducer calibration and wiring to IOB.
Check for 5.0 V reference voltage between IOB connectors.
Alm-252 ALM-252 Protective Limit - Low
Condenser Water Flow
As above As above
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 ow switches or water ow delta
P transducer calibration and wiring to IOB.
Check for 5.0 V reference voltage between IOB connectors.
Alm-253 ALM-253 Protective Limit - High
Discharge Temp
As above As above 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 ow and temperature.
Check for proper inlet guide vane and optional diuser actuator
operation.
Check for COMP DISCHARGE TEMP > 220 deg F.
Check for fouled tubes, plugged water strainers, or non-condensable
in the condenser.
Alm-254 ALM-254 Protective Limit - Low
Evap Refrigerant Temp
As above As above
Check for proper refrigerant charge.
Check oat valve operation.
Check for closed condenser liquid line isolation valve.
If problem occurs at high load, check for low condenser pressure which
causes inadequate refrigerant ow through condenser asc orices.
Check for proper chilled water ow and temperature. Conrm that
condenser water enters bottom row of condenser tubes rst, reversed
condenser water ow may cause refrigerant to stack in the condenser.
Check EVAPORATOR PRESSURE transducer and EVAP REFRIG
LIQUID TEMP and LEAVING CHILLED WATER sensors. Check for
division plate gasket bypass.
Check for fouled tubes.
Check pressure transducer and temperature sensor wiring to the IOB.
Alm-255 ALM-255 Protective Limit - High
Motor Temperature
As above As above Check COMP MOTOR WINDING TEMP accuracy and wiring to IOB.
Check motor cooling line and spray nozzle for proper operation, or
restrictions.
Check motor cooling lter/drier and isolation valves.
Look for refrigerant ow through motor cooling line sight glass.
Check for excessive starts within a short time span.