Daikin ARK25BVMB, Service Manual

Page: 135 / 201

Check SiBE04-302
126 Service Diagnosis
5.1.9 Capacitor Voltage Check
Check No.12 < 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.
< Measuring positions >
Take measurements at the power transistor (+) and (-) terminals in the same way as described
in section 1.
Set the multi-tester to DC and VOLTAGE RANGE before measurement.
∗
Since capacitor (+) and (-) are connected to power transistor (+) and (-), capacitor voltage
can be measured at the power transistor (+) and (-) terminals.
5.1.10 Power Transistor Check
Check No.13
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>
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