Domestic Air Conditioner
7 Service Diagnosis
7.1 Caution for Diagnosis
The operation lamp flashes when any of the following errors is detected.
1.When a protection device of the indoor or outdoor unit is activated or when the thermistor
malfunctions, disabling equipment operation.
2.When a signal transmission error occurs between the indoor and outdoor units.In either
case, conduct the diagnostic procedure described in the following pages.
7.2.Problem Symptoms and Measures
Sympt
R
m
Check Item
Details of Measure
None of the units
operates
Check the power supply.
Check to make sure that the rated voltage is supplied.
Check the indoor PCB
Check to make sure that the indoor PCB is broken
Operation
sometimes stops.
Check the power supply.
A power failure of 2 to 10 cycles can stop air conditioner
operation.
Equipment
operates but does
not cool, or does
not heat (only for
heat pump)
Check for faulty operation
of
the
electronic
expansion valve.
Set the units to cooling operation, and compare the
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.
Diagnosis by service port
pressure and operating
current.
Check for insufficient gas.
Large operating
noise and
vibrations
Check the installation
condition.
Check to make sure that the required spaces for
installation (specified in the Technical Guide, etc.) are
provided.
HSU12/18VHJ(DB)
Functions and control
54
Summary of Contents for HSU12VHJ(DB)
Page 3: ...12 VHJ DB 101 101 102 106 ...
Page 18: ...Domestic Air Conditioner PCB 2 CN1 CN2 CN3 CN4 CN5 CN6 CN7 CN11 CN10 15 HSU12 18VHJ DB ...
Page 21: ... Domestic Air Conditioner PCB 2 CN1 CN2 CN3 CN4 CN5 CN6 CN7 CN11 CN10 18 HSU12 18VHJ DB ...
Page 95: ...Loosen the top panel screws 1 2 Lift the top panel HSU12 18VHJ DB Removal Procedure 92 ...
Page 97: ...9 3 2 Removal of Electrical Box HSU12 18VHJ DB Removal Procedure 94 ...
Page 98: ...9 3 3 Removal of Fan and Fan Motor HSU12 18VHJ DB Removal Procedure 95 ...
Page 99: ...2 Loosen the fixing screws and remove the motor HSU12 18VHJ DB Removal Procedure 96 ...
Page 100: ...9 3 4 Removal of fan motor Bracket and Partition HSU12 18VHJ DB Removal Procedure 97 ...
Page 101: ...and remove the reactor Loosen the screw HSU12 18VHJ DB Removal Procedure 98 ...
Page 104: ... SSHQGL SSHQGL 3LSLQJ LDJUDPV 68 9 101 ...
Page 109: ...10 3 Circuit Diagrams 10 3 1 INDOORUNIT FOR12K Appendix HSU12 18VHJ DB 106 ...