20
Compressor
(MC)
INNER
PROTECTOR
MU-GA20/GA25VB
150
i
5°C OPEN
90
i
10°C CLOSE
OVERLOAD
RELAY
MU-GA35VB
140
i
5°C OPEN
75°C
i
5°C CLOSE
Part name
Outdoor fan
motor
(MF)
INNER FUSE
145
i
2°C
CUT OFF
Check method and criterion
Measure the resistance between the terminals with a tester.
(Coil wiring temperature –10°C ~ 40°C)
Measure the resistance between the terminals with a tester.
(Coil wiring temperature –10°C ~ 40°C)
Figure
P
R
C
S
RED
BLK
WHT
MAIN
AUX.
R
R
C
S
MAIN
AUX.
Normal
MU-GA20/GA25VB
323 ~ 396
Ω
241 ~ 296
Ω
189 ~ 233
Ω
270 ~ 332
Ω
WHT-BLK
BLK-RED
WHT
RED
BLK
MAIN
AUX.
FUSE
MU-GA20VB -
MU-GA25VB -
MU-GA35VB -
E1
E1
E1
Normal
MU-GA20/GA25VB
3.41~4.18
Ω
5.41~6.63
Ω
2.46~3.01
Ω
4.79~5.56
Ω
C-R
C-S
Abnormal
Open or short-circuit
MU-GA35VB
Abnormal
Open or short-circuit
MU-GA35VB
P INNER PROTECTOR
Color of
lead wire
9-3. Trouble criterion of main parts
A
A
Check of MU & MUX TYPE / MUH & MXZ TYPE SWITCH OVER
Start
Turn OFF the power supply (indoor / outdoor unit).
Set switch (SW2-
2
) on the indoor electronic
control P.C. board to MU type.
w
1
Does the unit operate?
OK
Yes
No
Refer to the
"Instruction of
troubleshooting."
w
1 Set the switch (SW2-
2
) on indoor electronic control P.C. board to
MU type, when the outdoor unit is MU type.
If the setting is MUH or MXZ type, the unit does not work.
Refer to 9-4. MU & MUX TYPE / MUH& MXZ TYPE SWITCH OVER AND
AUTO RESTART FUNCTION on service manual OB385 or OB393.
When OPERATION INDICATOR lamp flashes 0.5-second intervals.
Outdoor unit doesn’t operate.
Indoor unit MSC type
9-4. Troubleshooting flow
MU-GA35VB
MU-GA20/GA25VB
R OVERLOAD RELAY
OB386.qxp 05.1.14 9:44 Page 20
