II.12 CHECKLIST
1 - OUTLET PRESSURE HIGH
Insufficient cooling air at air-side exchanger:
Fan does not run:
Excessive refrigerant charge.
2 - OUTLET PRESSURE LOW
Insufficient refrigerant charge.
Mechanical problems in the compressor:
3 - INLET PRESSURE HIGH
Excessive thermal load:
Irregular operation of the expansion valve:
Mechanical problems in the compressor:
4 - INLET PRESSURE LOW
Insufficient refrigerant charge.
Filter partially obstructed (appears frosted):
Irregular operation of the expansion valve:
Presence of air in the water system:
Insufficient water flow:
5 - THE COMPRESSOR DOES NOT START
Microprocessor board alarm:
No voltage, switch open:
Overload protection triggered:
No request for cooling with user system set point correct:
Working set point too high:
Defective contactors:
Compressor electric motor failure:
6 - THE COMPRESSOR MAKES A BUZZING NOISE
Incorrect power supply voltage:
Compressor contactor stuck:
Mechanical problems in the compressor:
7 - THE COMPRESSOR STARTS AND STOPS
Faulty low pressure switch:
Insufficient refrigerant charge.
Refrigerant line filter clogged (appears frosted):
Irregular working of the expansion valve:
8 - THE COMPRESSOR STOPS
Faulty high pressure switch:
Insufficient cooling air at air-side exchanger:
Excessive ambient temperature:
Excessive refrigerant charge.
9 - THE COMPRESSOR IS NOISY AND VIBRATES
Compressor is pumping liquid, excessive refrigerant fluid in crankcase:
Mechanical problems in the compressor:
Unit running at the limit of specified conditions of use.
10 - THE COMPRESSOR RUNS CONTINUOUSLY
Excessive thermal load:
Working set point too low in cooling cycle (too high in heating cycle):
Insufficient refrigerant charge.
Refrigerant line filter clogged (appears frosted):
Control board faulty:
Irregular working of the expansion valve:
Compressor contactor stuck:
Poor ventilation to the coil:
11 - THE FAN DOES NOT WORK OR STARTS AND STOPS
Thermal protection activated:
12 - THE CIRCULATION PUMP DOES NOT START
Lack of voltage to the pump unit:
Pump blocked:
Pump motor failure:
Remote ON/OFF switch in OFF position:
PROBLEM
RECOMMENDED ACTION
check the technical clearances and whether the coil is obstructed.
check whether the fan is working.
drain the excess.
1 - identify and eliminate any leaks;
2 - restore correct charge.
replace compressor
check system sizing, infiltrations and insulation.
check operation.
replace compressor
1 - identify and eliminate any leaks;
2 - restore correct charge.
replace filter.
check operation.
bleed the water system.
check that the pump is working.
identify alarm and take appropriate action.
close the switch.
1 - reset the switch;
2-check the unit at start up.
check and if necessary wait for cooling request.
check and if necessary readjust set-point.
replace contactor.
check for short circuit.
check voltage, investigate causes.
replace contactor.
replace compressor
check pressure switch calibration and operation.
1 - identify and eliminate any leaks;
2 - restore correct charge.
replace filter.
check operation.
check pressure switch calibration and operation.
1 - check clearances and make sure coils are not obstructed;
2 - check that the fan is working.
check unit operation limits.
discharge surplus refrigerant.
1 - check operation of the expansion valve;
2 - check superheating;
3 - adjust superheating, if necessary replace expansion valve.
replace compressor
check unit operation limits.
check system sizing, leakage and insulation.
check setting and reset.
1 - identify and eliminate any leaks;
2 - restore correct charge.
replace filter.
replace the board.
check operation.
replace contactor.
1 - check clearances and make sure coils are not obstructed;
2 - check fan function.
1 - check for short-circuits;
2 - replace the fan.
check electrical connections.
unblock the pump.
replace the pump.
put in ON position.
37
Compact-Y SM