Section II :: Installation and maintenance
31
II.4.2.4 Check-list
PROBLEM
RECOMMENDED ACTION
1 - HIGH FLOW PRESSURE
Insufficient cooling air in air side heat exchanger:
check clearances and make sure coil is not obstructed;
The fan does not work:
check fan operation.
Excessive refrigerant charge:
drain the excess.
2 - LOW FLOW PRESSURE
Insufficient refrigerant charge:
1 - detect and eliminate any leaks;
2 - restore correct load.
Mechanical problems in the compressor:
replace compressor.
3 - HIGH INTAKE PRESSURE
Excessive thermal load:
check system sizing, infiltrations and insulation.
Irregular operation of the expansion valve:
check operation.
Mechanical problems in the compressor:
replace compressor.
4 - LOW INTAKE PRESSURE
Insufficient refrigerant charge:
1 - detect and eliminate any leaks;
2 - restore correct load.
Filter partially obstructed (appears frosted):
replace filter.
Irregular operation of the expansion valve:
check operation.
5 - COMPRESSOR: DOES NOT START
Microprocessor board alarm:
identify alarm and take appropriate action.
Phase sequence control device in alarm (yellow light)
reverse the sequence of the phases.
No voltage, switch open:
close the switch.
Overload protection triggered:
1 - reset the switch;
2 - check the unit at start up.
No request for cooling with user system set point correct:
check and if necessary wait for cooling request.
Working set point too high:
check and if necessary readjust set-point.
Defective contactors:
replace contactor.
Compressor electric motor failure:
check short circuit.
6 – CRANKCASE HEATER DOES NOT WORK
Lack of electrical power supply:
check power supply and auxiliary fuses.
Crankcase heater interrupted:
check and replace the crankcase heater.
7 - COMPRESSOR: BUZZING CAN BE HEARD
Incorrect power supply voltage:
check voltage, investigate causes.
Compressor contactor stuck:
replace contactor.
Mechanical problems in the compressor:
replace compressor.
8 - COMPRESSOR: FUNCTIONS INTERMITTENTLY
Faulty low pressure switch:
check pressure switch calibration and operation.
Insufficient refrigerant charge:
1 - detect and eliminate any leaks;
2 - restore correct load.
Refrigerant line filter clogged (appears frosted):
replace filter.
Irregular operation of the expansion valve:
check operation.
9 - COMPRESSOR: YES STOP
Faulty high pressure switch:
check pressure switch calibration and operation.
Insufficient cooling air in air side heat exchanger:
1 - check clearances and make sure coils are not obstructed;
2- check fan function.
Excessive ambient temperature:
check unit operation limits.
Excessive refrigerant charge:
drain the excess.
10 - COMPRESSOR: FUNCTIONS NOISILY-INTERMITTENTLY
Compressor is pumping liquid, excessive increase in refrigerant fluid in
crankcase:
1 - check operation of the expansion valve;
2 - check overheating;
3 - adjust overheating, replace the expansion valve if required.
Mechanical problems in the compressor:
replace compressor.
Unit running at the limit of conditions for use:
check unit functioning limits.
11 - COMPRESSOR: FUNCTIONS CONTINUOUSLY
Excessive thermal load:
check system sizing, leaks and insulation.
Work set point too low in cooling cycle (high in heating cycle):
check calibration and reset.
Insufficient refrigerant charge:
1 - detect and eliminate any leaks;
2 - restore correct load.
Refrigerant line filter clogged (appears frosted):
replace filter.
Control board faulty:
replace the board.
Irregular operation of the expansion valve:
check operation.
Compressor contactor stuck:
replace contactor.
Poor ventilation of the coils:
1 - check clearances and make sure coils are not obstructed;
2 - check fan function.
12 - FAN: IT DOES NOT START, IT SWITCHES ON AND OFF
Circuit breaker protection activated:
1- check for short-circuits;
2-replace the motor.
Summary of Contents for REV Series
Page 20: ...NOTE ...
Page 21: ...REV 16 32 H58043 01 15 PS RM ...
