Mitsubishi Heavy Industries FDUA160AVSAVH Service Manual page 59

(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
between phases?
NO
Normal
-
If there is a 10% or greater difference
in the current in different phases.
(except during acceleration or deceleration)
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 control
incorporated.
Models FDCA160, 200VSA
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.
58
-
'21 • PAC-SM-398
Replace the outdoor
unit inverter PCB
Normal value (W)
Models 160, 200
Scores of M
Approx. 8.9M
Scores of M
Approx. 4.6M
Approx. 4.8M
Scores of M