Power Transistor Check - Daikin G-Series Service Manual

Check
5.1.9 Inverter Units Refrigerant System Check
Check No.11
Refrigerant system check
Check for refrigerant leakage.
See the section on refrigerant
shortage detection.

5.1.10 Power Transistor Check

Check No.13
Note: Check to make sure that the voltage between (+) and (–) of the diode bridge (DB1) is approx.
0 V before checking.
Negative (–) terminal of
tester (positive terminal
(+) for digital tester)
Positive (+) terminal of
tester (negative terminal
(–) for digital tester)
Resistance in OK
Resistance in NG
218
Is the discharge
thermistor
disconnected from the
holder?
NO
Is the
temperature of
the four way valve
suction pipe
abnormally high?
NO
Disconnect the compressor harness connector from the outdoor unit PCB. To disengage the
connector, press the protrusion on the connector.
Follow the procedure below to measure resistance between the terminals of the DB1 and
the terminals of the compressor with a multi-tester. Evaluate the measurement results for a
judgment.
YES
YES
DB1 (+) UVW
UVW DB1 (+)
several kΩ ~ several MΩ
SiBE12-933_A
Correct the problem.
Four way valve defective.
Replace the four way valve.
Replace the refrigerant.
(R8428)
DB1 (–)
UVW DB1 (–)
0 Ω or ∞
Service Diagnosis
UVW