Check
SIE-86
76
Service Diagnosis
6. Check
6.1
How to Check
6.1.1
Power transistor check
Capacitor voltage check
(CHEK 3)
Check No.3
1. Power transistor check
Note:
Check to make sure that the voltage between the terminal of Power transistor (+) and (-) is approx. 0 volt
before checking power transistor.
< Measuring method >
Disconnect the compressor harness connector from the outdoor unit PCB. To disengage the connector,
press the protrusion on the connector.
Then, follow the procedure below to measure resistance between power transistor (+) and (-) and the U, V
and W terminals of the compressor connector with a multi-tester. Evaluate the measurement results for a
pass/fail judgment.
<Power transistor check>
<Measuring positions>
2. Capacitor voltage check
< Measuring method >
Before measuring, operate the unit for several minutes, then shut down the operation by force using the
circuit breaker.
If the unit is shut down using the remote controller instead of the circuit breaker, the capacitor
discharges the electric load, thus disallowing accurate measurement.
Note:
The charge section is applied with high voltage. Therefore, exercise caution during measurement to
prevent electric shock.
Negative (-) terminal of
tester (positive terminal (+)
for digital tester)
Power transistor (+)
UVW
Power transistor (-)
UVW
Positive (+) terminal of
tester (negative terminal (-)
for digital tester)
UVW
Power transistor (+)
UVW
Power transistor (-)
Normal resistance
Several k
Ω
to several M
Ω
(
∗
)
Unacceptable resistance
Short (0
Ω
) or open
Si-86.book Page 76 Friday, June 23, 2000 10:26 AM
