Mitsubishi Heavy Industries SRK100VNXWZRF Service Manual page 61

(6) 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 you do not have a diagnostic checker for judging
if the inverter is defective, measure between the terminal
on the inverter PCB, judge whether the power transistor is
defective or not.
• Disconnect the compressor, then measure with the
control incorporated.
Models FDC100VNX-W, 100VSX-W
Tester
Terminal Terminal
(+) (-)
P N
N P
P U
P V
P W
N U
N V
N W
U P
V P
W P
U N
V N
W N
If the measured values range from 0 - several kW, there is a possibility
that the elements are damaged, so replace the power transistor parts.
60
- -
'22 • PAC-SM-422
Replace the outdoor
unit inverter PCB
Normal value (W)
FDC100 FDC100
VNX-W VSX-W
Approx. 230 k Approx. 50 k
Approx. 570 k Approx. 525 k
Approx. 420 k Approx. 260 k
Approx. 215 k
Approx. 250 k
Approx. 235 k
Approx. 480 k Approx. 280 k