AUX air conditioner service manual
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lower than rated value;
② Over-current on compressor: check if heat protector on the compressor pump shell has broken
off. Normally, heat protector will break off if current is excessively large. Heat protector of
three phase motor is embedded in motor winding in pump shell. Check junction box on the
pump shell by using universal meter, both for single phase and three phase motor; if winding
is current off, protector has cut off the power. Wait for 5 minutes, protector will restore to
original position.
③ Fan overheats or heat protector has damaged (refer to fan of outdoor unit). When fan runs
under excess load, its winding temperature will rise, and heat protector will break off and
power will be cut off. Check if inlet wire connector of fan is current on. If not, it shows that
heat protector works, and it will restore to original position after cooling down. If protector
fails to restore, it has been damaged and need to be replaced.
④ Poor contact of connector. Fan motor is also jointed with socket connector, connector lugs
may not contact well. In addition, check if wire in junction box of compressor pump shell is
loose or does not contact well;
⑤ AC contactor loops break off. If loops break off, contact points can not be closed, so that
power can not enter the motor;
⑥ Electronic circuit control panel has been broken;
⑦ High pressure switch has broken. If high voltage switch has been broken, connection lugs
cannot contact well. Check connection lugs with universal meter.
⑧ Trip of low pressure switch. When refrigerating system runs normally, connection lugs of low
voltage switch contact well. When refrigerating system has trouble or refrigerant leaks,
pressure in the system will decrease below trip point; low pressure switch will trip and cut off
service power.
(3)Air conditioner shuts down short after it starts up
① Excess high discharge pressure, which causes high pressure switch tripping;
② Excess low suction pressure causing trip of low pressure switch;
③ Fan motor has burnt out;
④ Heat protector trips.
(4)When air conditioner starts up, power indicator lights, indoor fan runs but compressor fails to
operate
It shows that there’s no problem in refrigerating system and fan system, but people operate the air
conditioner in wrong way or thermostat switch has broken, therefore, trouble light doesn’t blink.
① Wrong buttons have been pushed Air conditioner may be in ventilation situation instead of
refrigerating situation.
② Temperature has not reached set value. When set temperature of thermostat switch is higher
than room temperature, connection lugs of temperature controller opens all along,
refrigerating system cannot run. Proper temperature shall be set.
③ Sensor (thermal resistor) of temperature controller has broken, which cause improper
temperature control. Check resistance and temperature to decide whether it has broken
according to corresponding value of resistance/temperature.
3. Troubleshooting for compressor motor
There’re two types of motors for totally enclosed compressor of air conditioner: single- phase and
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