General Check - McQuay MWM Service Manual

MCQUAY Service Guide Book

7.4 General Check

When any air conditioner malfunction is noted, immediately switch off the power supply to the unit and
contact the local dealer if necessary.
Problem Symptom
The unit does not
work
Fan does not work
Fan work, but
compressor does
not work
Air conditioner work
but cooling not
satisfactory
The air flow is too
low
The remote
controller light is dim
Check Item
Check the power supply
Check the fuse
Check the remote controller timer
setting
Check the power supply
Check the fan motor capacitor
Check the fan motor
Check the switch
Check if the thermostat setting too
high
Check the compressor capacitor
Check the compressor
Check the compressor contactor
Check if the thermostat setting too
high
Check if the condenser coil dirty
Check the condenser installation
condition
Diagnosis by service port pressure
and operating Current
Check the air filter
Check the fan / blower condition
Check the battery
Suggested Action
Check to make sure that the rated voltage
is supplied.
Check and replace the fuse.
Make sure the delay timer is set correctly.
Check to make sure that the rated voltage
is supplied.
Check and replace the capacitor.
Check and replace the fan motor.
Check and change the switch.
Reset thermostat.
Check and replace the capacitor.
Check and replace the compressor.
Check and replace the contactor.
Reset thermostat.
Clean the condenser coil.
Make sure the condenser is installed
According to factory's recommendation.
Check for insufficient refrigerant.
Check and make sure the air filter is clean.
Check and make sure that the fan / blower
are in good condition.
Check and replace the battery.
Make sure the batteries are correctly
inserted.
75
Diagnosis