-
118
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Compressor operation
Replace the outdoor
unit inverter
Normal
NO
YES
YES
NO
NO
YES
Is the power
transistor module
cracked or burnt?
Is there a
short circuit between the
power transistor module
terminals?
❇
1
Is the balance
between the compressor
current phases good?
If there is a 10% or greater difference
in the current in different phases.
(except during acceleration or deceleration)
Power transistor module (including drive circuit) check method
❇
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 terminal.
P: Power transistor P terminal,
U: End of red harness to compressor
N: Power transistor N terminal,
V: End of white harness to compressor
W: End of black or blue harness to compressor
Normal values (
Ω
)
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.
If the measured values range from 0 ~ several k
Ω
, there is a
possibility that the elements are damaged, so replace the
power transistor parts.
Tester
Terminal (+)
P
N
P
P
P
N
N
N
U
V
W
U
V
W
Terminal (-)
N
P
U
V
W
U
V
W
P
P
P
N
N
N
0 ~
(Numerical value rises.)
Several M
(Numerical value rises.)
302
Approx. 670 k
Approx. 4.4 M
Approx. 4.4 M
Approx. 650 k
Approx. 4.8 M
Approx. 4.9 M
Approx. 650 k
