12KHR-N
3 – 11
1. Checking procedures
No
.
Item
Check method
Normal value/condition
Remedy
1
Preparation
Disconnect compressor cords (white,
orange, red: 3 wires) from compres-
sor terminals, and connect simulated
load (lamp used as load).
Operate air conditioner in cooling or
heating test operation mode.
2
Inverter DC power supply
voltage check
Measure DC voltage between IPM
pins (20) and (24).
320 VDC
Replace control PWB.
Replace diode bridge.
Correct soldered section of Fas-
ten tabs (BT1,2,5,6,10,11,
JPL1,2,5,6) on control PWB.
(Repair solder cracks.)
3
IPM circuit check
Check that 3 lamps (load) light.
Check position detection voltage (+15
V, 5 V) on control PWB.
Each voltage should be normal.
All 3 lamps (load) should light with
same intensity.
Replace control PWB.
4
Compressor check
Measure compressor coil resistance
(for each phase of U, V and W).
Use multi-meter or digital tester capa-
ble of displaying two digits right of the
decimal point (0.01
:
).
Resistance value at 20
q
C --- 0.65
:
Correct connections at compres-
sor terminals.
Replace compressor.
5
Expansion valve check
Measure expansion valve coil resis-
tance.
Each phase 46
r
3
:
(at 20
q
C)
Replace expansion valve.
6
Final check
Turn off power, and connect compres-
sor cords to compressor.
Operate air conditioner.
Measure DC voltage between IPM
pins (20) and (24).
Compressor should operate nor-
mally.
320 VDC or higher.
Replace control PWB.
Replace outdoor unit thermistor.
Replace compressor (in case of
compressor lock).