Carrier PIC 5+ - Page 38

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Alm-256 ALM-256 Protective Limit - High
Bearing Temperature
As above As above Check oil heater for proper operation, conrm that oil heater is de-
energized when compressor is running.
Check for low oil level, partially closed oil line isolation valves, or
clogged oil lter.
Check oil cooler refrigerant thermal expansion valves, conrm that
expansion valve bulbs are secured to the oil lines and insulated.
Check COMP BEARING TEMP sensors accuracy and wiring to IOB.
This fault can result from excessive operation at low load with low
water ow to the evaporator or condenser.
Very high discharge and volute temperatures may increase the oil
sump temperature.
Elevated sump temperature may result from an excessively high oil
level reaching the bottom of the bull gear causing it to churn the oil.
Alm-257 ALM-257 Protective Limit - High
Condenser Pressure
As above As above Check CONDENSER PRESSURE.
Check for high Condenser Water temperatures, low water ow, fouled
tubes.
Check for division plate/gasket bypass or plugged condenser water
strainers.
Check for noncondensables in condenser.
Check CONDENSER PRESSURE transducer wiring and accuracy
to IOB .
Congure COND PRESS OVERRIDE in conguration screen.
This Alarm is not caused by the High Condenser Pressure Switch.
Alm-258 ALM-258 Protective Limit -
Spare Safety Device
As above As above Spare safety input has been closed
Alm-259 ALM-259 Protective Limit -
Excessive Compressor Surge
As above As above
Five SURGE PROTECTION COUNTS occurred within SURGE TIME
PERIOD. VFD Only: Surge prevention alarm declared when ACTUAL
VFD SPEED is at least 90%.
Check for high condenser water temperatures, low water ow, fouled
tubes.
Check CONDENSER APPROACH.
Check condenser water strainers.
Check for division plate/gasket bypass. Check for noncondensables in
condenser.
Check surge prevention parameters in OPTIONS screen.
Compare cooling tower control settings and performance against design/
selection temperatures across the entire operating range of the chiller.
Check EVAPORATOR APPROACH and chilled water ow.
Alm-260 ALM-260 Protective Limit -
Compressor Start Relay Start
failure
As above As above Check motor starter 1M contactor wiring
Check ISM current sensors
Alm-261 ALM-261 Protective Limit -
Evaporator Frozen
As above As above Check CALC EVAP SAT TEMP, EVAP REFRIG LIQUID TEMP, and
EVAP REFRIG TRIPPOINT.
Check for proper refrigerant charge.
Check oat valve operation.
Conrm that optional refrigerant liquid line isolation valve is open.
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 sensor.
Check for evaporator water box division plate gasket bypass. Check
for fouled tubes.
Alm-262 ALM-262 Protective Limit -
Condenser Frozen
As above As above
The Cond Sat refrig Temp is less than the Condenser Freeze Point.
Check Condenser Freeze Point in conguration.
Condenser water too cold or chiller shut down with brine below 32 deg
F in cooler so equalization temperature in chiller approached 32 deg F.
Check CONDENSER PRESSURE transducer and wiring to IOB.
Check Condenser Water Temperature sensors and wiring to IOB.
Check refrigerant charge.
Alm-263 ALM-263 Protective Limit -
Invalid Diuser Cong
As above As above Check SRD congurations
Alm-264 ALM-264 Protective Limit -
Diuser Position Fault
As above As above Conrm that Diuser Option in SRD Conguration screen has not
been Enabled if compressor does not have a split ring diuser. May
indicate rotating stall condition.
Check rotating stall transducer wiring accuracy and sealing.
Check diffuser schedule and guide vane schedule in SRD
Conguration screen.
Check for proper operation of diuser and inlet guide vane actuators
including inlet guide vane calibration.
Check diuser actuator coupling for rotational slip.
Check for electrical noise in IOB Diuser Pressure wiring.
Do not continue to operate compressor except for diagnostic purposes.
Alm-265 ALM-265 Protective Limit -
Refrigerant Leak
Manual As above REFRIGERANT LEAK OPTION is Enabled and the REFRIGERANT
LEAK SENSOR output exceeded REFRIGERANT LEAK ALARM mA.
Check for refrigerant leaks.
Check leak detector for proper operation.
Check REFRIGERANT LEAK ALARM mA setting in the OPTIONS
screen.
Check 4-20 mA or 1-5 V output from refrigerant leak sensor to IOB
J15-5Conrm that IOB SW2 dip switch 1 is in the correct position.