Power Transistor Module (Including The Driver Pcb) Inspection Procedure - Mitsubishi Electric FDF100VSXVD Technical Manual

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Power transistor module (including the driver PCB) inspection procedure

short circuit between the
power transistor module
Compressor operation
Is there any difference in
the compressor current
* 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
Is the power
YES
transistor module
cracked or burnt?
NO
Is there a
YES
terminals? 1
NO
YES
If there is a 10% or greater difference
between phases?
in the current in different phases.
(except during acceleration or deceleration)
NO
Normal
Check for a power transistor short circuit.
• When y o u do not hav e a diagnostic check e r for j u dging if the inv e rter
is defectiv e , measure between the terminals of the power transistor
parts, j u dge whether the power transistor is defectiv e or not.
• Disconnect the compressor, then measure with the controller
incorporated.
Tester
Terminal Terminal
(+ ) (-)
P N
(Numerical
N P
v a lue rises.)
P U
Sev e ral M
P V (Numerical
v a lue rises.)
P W
N U
N V Approx . 6 5 0 k
N W
U P Approx . 6 7 0 k
V P Approx . 4.4 M
W P Approx . 4.4 M
U N Approx . 6 5 0 k
V N Approx . 4.8 M
W N Approx . 4.9 M
If the measured v a lues range from 0 ~ sev e ral k W , there is a possibility that the
elements are damaged, so replace the power transistor parts.
- 140 -
'11 • PAC-T-160
Replace the outdoor
unit inverter PCB
Note(1) In models 200 and 250, also
replace the power transistor.
Normal v a lues (
Model
Model 71
10 0 ~ 1 40
0 ~ Approx . 1 M
Approx .
30 0 ~ 4 0 0
0
Approx . 1.2 M
Approx . 1.3 M
0
)
Model
20 0 , 250
Scores of M
A few of M
Scores of M
Scores of M
Scores of M
Hundreds of K
Hundreds of K
Hundreds of K
Hundreds of K
Hundreds of K
Hundreds of K
Scores of M
Scores of M
Scores of M