McQuay MWM - General Check for Malfunctions

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