IVT 12KHR-N Service Manual page 33

1. Checking procedures
No Item
.
1 Preparation
2 Inverter DC power supply
voltage check
3 IPM circuit check
4 Compressor check
5 Expansion valve check
6 Final check
Check method
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.
Measure DC voltage between IPM
pins (20) and (24).
Check that 3 lamps (load) light.
Check position detection voltage (+15
V, 5 V) on control PWB.
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 ).
Measure expansion valve coil resis-
tance.
Turn off power, and connect compres-
sor cords to compressor.
Operate air conditioner.
Measure DC voltage between IPM
pins (20) and (24).
Normal value/condition
320 VDC
Each voltage should be normal.
All 3 lamps (load) should light with
same intensity.
Resistance value at 20 C --- 0.65
Each phase 46 3 (at 20 C)
Compressor should operate nor-
mally.
320 VDC or higher.
3 – 11
12KHR-N
Remedy
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.)
Replace control PWB.
Correct connections at compres-
sor terminals.
Replace compressor.
Replace expansion valve.
Replace control PWB.
Replace outdoor unit thermistor.
Replace compressor (in case of
compressor lock).