Power Transistor Module (Including The Driver Pcb) Inspection Procedure - Mitsubishi Heavy Industries FDTC40ZHXV Technical Manual

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Power transistor module (including the driver PCB) inspection procedure

* 1
Power transistor module terminal short circuit check procedure
Disconnect the compressor wiring, then conduct a short circuit check.
P-U, P-V, P-W
N-U, N-V, N-W
Check between the P-N terminals.
Bring the tester probes in contact with the following
places on each te rminal.
P: Power transistor P terminal,
N: Power transistor N terminal,
U: End of red harness to compressor
V: End of white harness to compressor
W: End of black or blue harness to compressor
Check for a power transistor short circuit.
• When you do not have a diagnostic checker for judging if the inverter
is defective, measure between the terminals of the power transistor
parts, judge whether the power transistor is defective or not.
• Disconnect the compressor, then measure with the controller
incorporated.
Tester
Terminal Terminal
Model 71
(+) (-)
P N
(Numerical
N P
value rises.)
P U
Several M
P V (Numerical
value rises.)
P W
N U
N V Approx. 650 k Approx. 1.2 M
N W
U P Approx. 670 k
V P Approx. 4.4 M
W P Approx. 4.4 M
U N Approx. 650 k
V N Approx. 4.8 M
W N Approx. 4.9 M
If the measured values range from 0 ~ several kW, there is a possibility that the
elements are damaged, so replace the power transistor parts.
265
– –
Normal values (Ω)
Model
100~140
0 ~ Approx. 1 M
Scores of M
Approx.
A few of M
300~400
Scores of M
0 Scores of M
Scores of M
Hundreds of K
Hundreds of K
Hundreds of K
Hundreds of K
Approx. 1.3 M Hundreds of K
Hundreds of K
Scores of M
0 Scores of M
Scores of M
Model
200, 250