Malfunction (Parts) Check Method - IVT 12KHR-N Service Manual

12KHR-N

[6] MALFUNCTION (PARTS) CHECK METHOD

1. Procedure for determining defective outdoor unit IPM/compressor
The following flow chart shows a procedure for locating the cause of a malfunction when the compressor does not start up and a DC overcurrent indi-
cation error occurs.
Connect power cord
to AC outlet.
Check 220-240 VAC
between (1) and (N)
on outdoor unit PWB.
YES
NO
Is LED1 on outdoor
unit flashing?
YES
Using remote control,
operate air conditioner
so that compressor
starts.
Compressor starts up.
Immediately
after startup
YES
Does LED1 indicate
DC overcurrent error?
NO
YES
Does LED1 indicate
rotation error?
NO
Normal
CAUTION: Please take care for electrical shock when you work to change defective parts or disconnect wires of defective application.
The outdoor unit has energy changed for a while even after unplugging the power supply cord.
After changing the part or unit, please retry check procedure from the beginning.
No
(unlit)
Does LED1 remain lit?
YES
Serial signal error.
Check inter-unit wiring.
Check indoor and
outdoor unit PWBs.
Replace outdoor unit
PWB.
Check compressor.
2/3-way valve closed.
Refrigerant shortage.
Replace outdoor unit PWB.
NO
Replace compressor.
NO
Check 320 VDC between
pins IPM (20) and (24)?
YES
NO
FUSE and+12 V, +15 V,
+18V on PWB
YES
(LED1 is still off)
Replace outdoor unit PWB.
YES
Replace expansion valve.
3 – 8
Replace outdoor unit PWB.
Disconnect (CN3) lead
wires of FAN motor.
Disconnect (CN12)
expansion valve.
NO
Replace outdoor unit PWB.
LED1 is flashing.
NO
LED1 is flashing.
YES
Replace FAN motor.