Check
SiSG121917E
179
Part 6 Service Diagnosis
90 class
To prevent electrical shock, use a multimeter to check that the voltage between FU2 and
DC_N2 is 50 V or less.
The surface of the test points (FU2, DC_N2) may be covered with the coating. Be sure to
make firm contact between the multimeter probes and the test points.
8.14 Power Module Check
Check No.22
Check to make sure that the voltage between (+) and (–) of the power module is approximately
0 V before checking.
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 (+) or (–) terminal of the
power module and the U, V, or W terminal of the compressor with a multimeter. Evaluate the
measurement results referring to the following table.
FU2
DC_
N
2
(R21124)
M
u
ltimeter
(DC
v
oltage range)
FU2
DC_N2
Coating
PCB
Multimeter probe
(R21125)
Positive terminal (+) of
digital multimeter
Power module
(+)
UVW
Power module
(–)
UVW
Negative terminal (–) of
digital multimeter
UVW
Power module
(+)
UVW
Power module
(–)
Resistance is OK.
several k
~ several M
Resistance is NG.
0
or
