RHOSS CMA/E 14 Gebrauchsanweisung Seite 25

II.4.2.2 Check-list
Problem
1 – The compressor does not start
Supply voltage low:
Adjustment thermostat open:
Compressor contactor coil (KC) interrupted:
High pressure switch (PA) open:
Low pressure switch (PB) open:
Fan and compressor winding protection open:
2 – High suction pressure
Excessive thermal load in cooling cycle:
Excessive refrigerant charge:
3 - Low pressure switch malfunction (Pb).
Insufficient refrigerant charge:
Thermostat valve out of calibration:
Indoor unit coil iced up:
Evaporating section faulty:
4 - High pressure switch malfunction.
Condenser coil blocked in cooling cycle:
Excessive refrigerant charge:
Fan malfunction in cooling cycle:
5 - Low discharge pressure
Insufficient refrigerant charge:
Liquid pipe clogged:
Indoor unit air filter dirty:
Thermostat valve stuck:
6 - Crankcase heater does not work.
No power:
Crankcase heater faulty:
7 – Compressor windings protection open-circuit.
Windings overheated due to insufficient refrigerant charge:
Windings overheated due to excessive power absorption:
Windings overheated due to compressor malfunction:
Windings overheated due to high refrigerant temperature on suction line:
8 – No defrosting (CMR/E only).
Cycle reversing valve faulty:
The compressor is pumping liquid, excessive increase of coolant in sump.
Mechanical problems in the compressor.
Unit running in limit conditions.
9 – The compressor runs continuously
Excessive thermal load.
Working set point too low in cooling cycle (too high in heating cycle).
Insufficient coolant charge.
Coolant line filter clogged (appears frosted).
Control board malfunction.
Expansion valve malfunction.
Compressor contactor stuck:
Poor ventilation to the coil:
Unit under-sized:
Insufficient refrigerant charge:
Coolant line filter clogged (appears frosted).
Compressor contactor stuck:
10 - Fan does not start, or starts and stops
Contactor or capacitor faulty:
Windings overheated and thermal protection tripped:
Thermal overload protection triggered.
SECTION II: INSTALLATION AND MAINTENANCE
Recommended action
check and eliminate cause.
check calibration
replace contactor (KC).
see problem 4
see problem 5.
closes automatically when temperature falls.
check system sizing.
discharge excess refrigerant.
check contents of the circuit and top up.
reset the thermostat valve.
check the filter and airflow.
check the evaporating section.
check and clean coil.
check and reduce charge.
check fan operation.
check for leaks, repair and replenish.
check clogging and remove.
clean air filter.
reset the thermostat valve.
check electrical connections and auxiliary fuses.
check and, if necessary, replace heater.
check and replenish charge.
check operation of unit, condenser and power supply.
check and, if necessary, replace compressor.
check operation of the thermostat valve.
check and, if necessary, replace.
1 check expansion valve.
2 check superheating.
3 adjust superheating, if necessary replace expansion valve.
replace compressor
check unit working limits.
check system sizing, leakage and insulation.
check calibration 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.
check heating requirements.
recharge and check for leaks in circuit.
replace filter.
replace contactor.
check and, if necessary, replace.
check and, if necessary, replace.
1 check for short-circuits
2 replace contactor.
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