Daikin FCQ18PVJU Service Manual page 165

SiUS28-902_a
CHECK 3
Check for Fan Motor Connector
(1) Turn the power supply off.
(2) With the fan motor connector disconnected, measure the resistance between each pin, then
CHECK 4
Check for Power Transistor
Judgment is made through cable check with an analog tester.
(1) Do not touch the energized part (high voltage part) for at least 10 minutes after the power is
(2) Be sure to touch the ground terminal with a hand to release static electricity from the body
(3) Also with a tester, take measurements at the following spots and confirm that residual
(4) After checking the residual electric charge, remove the connector of the outdoor unit fan
(5) Remove the wire connecting the power transistor and the compressor. Remove it from the
(6) Using an analog tester, measure resistance and fill in the blanks in the following table.
Troubleshooting
make sure that the resistance is more than the value mentioned in the following table.
1 White
2 Orange
3 Brown
GND
4 Blue
5
6
7 Red
turned OFF.
(to prevent the PC board from being damaged).
electric charge of the power transistor is DC 50V or less.
Electrical
equipment box
Outdoor unit
fan connector
Front face
motor. When the outdoor unit fan is rotated by strong headwind, remove the connector of
the outdoor unit fan motor after confirming that the outdoor unit fan has stopped because
electrical energy is stored in the capacitor and there may be a risk of electric shock.
compressor terminal side. During this work, be careful not to deform the Faston terminal at
the end of the connecting wire.
In case of unbalanced resistance for one of the three phases in each table (when the
resistance value is equal to five times or more than the other resistance values), the power
transistor is broken.
In normal cases, each phase shows a similar resistance value.
Outdoor Unit
PC board
C+ C-
U V W
Red White Blue
U V W
Comp.
M1C
Troubleshooting by Indication on the Unified ON/OFF Controller
Measurement point
1 - 4
2 - 4
3 - 4
4 - 7
Ground terminal
Tester Resistance
Ω
(+) (-)
C+ U
C+ V
C+ W
∞
U C+
∞
V C+
∞
W C+
Judgement
1MΩ or more
100kΩ or more
100Ω or more
100kΩ or more
Residual voltage
measurement spot
Tester Resistance
Ω
(+) (-)
∞
C- U
∞
C- V
∞
C- W
U C-
V C-
W C-
158