11.3.Problem Symptoms and Measures
Symptom
Check Item
None of the units
Check the power supply.
operates
Check the indoor PCB
Operation
Check the power supply.
sometimes stops.
Check for faulty operation
of
Equipment
expansion valve.
operates but does
not cool, or does
not heat (only for
heat pump)
Diagnosis by service port
pressure and operating
current.
Large operating
Check the installation
noise and
condition.
vibrations
Details of Measure
Check to make sure that the rated voltage is supplied.
Check to make sure that the indoor PCB is broken
A power failure of 2 to 10 cycles can stop air conditioner
operation.
Set the units to cooling operation, and compare the
the
electronic
temperatures of the liquid side connection pipes of the
connection section among rooms to check the opening and
closing operation of the electronic expansion valves of the
individual units.
Check for insufficient gas.
Check to make sure that the required spaces for
installation (specified in the Technical Guide, etc.) are
provided.
35
Connector Wiring Diagram
Domestic Air Conditioner