Capacitor Voltage Check; Power Transistor Check - Daikin FLKS25BVMB Service Manual

Check

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.
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

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)
Positive (+) terminal of
tester (negative terminal
(-) for digital tester)
Normal resistance
Unacceptable resistance
110
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.
can be measured at the power transistor (+) and (-) terminals.
Power transistor UVW
(+)
UVW Power transistor
(+)
Several kΩ to several MΩ (∗)
Short (0 Ω) or open
SiBE05-311
Power transistor UVW
(-)
UVW Power transistor
(-)
Service Diagnosis