Mitsubishi Electric MXZ-SM72TAM-U1 Service Manual page 93

A
SW1
E ~
SW2
The silent mode and the demand control are selected by switching the DIP switch 9-2 on outdoor controller board.
It is possible to set it to the following power consumption (compared with ratings) by setting SW1, 2.
Silent mode
Demand control
8-7. How to check the parts
8-7-1. Checkpoints for each part
■ Thermistors
Disconnect the connector then measure the resistance with a multimeter (at the ambient temperature 50 to 86°F [10 to
30°C]).
Thermistors
TH4 (Compressor)
TH2 (HIC pipe)
TH3 (Outdoor liquid pipe)
TH6 (Suction pipe)
TH7 (Ambient)
TH8 (Heat sink)
■ Fan motor (MF1, MF2)
M
Measure the resistance between the connector pins with a multimeter (at the ambient temperature 68°F [20°C]).
Connector pins
1 - 4
5 - 4
6 - 4
7 - 4
* See the spec name plate indicated in the diagram for the model name of fan motor.
"X" in the model name of fan motor represents numbers and letters.
■ Solenoid valve coil <4-way valve> (21S4)
Measure the resistance between the terminals with a multimeter (at the ambient temperature 68°F [20°C]).
Normal
1725 ± 172.5 Ω
■ Motor for compressor (MC)
U
V
W
Measure the resistance between the terminals with a multimeter (at the ambient temperature 68°F [20°C]).
Normal
0.121 ± 0.006 Ω
■ Solenoid valve coil <Bypass valve> (SV1)
Measure the resistance between the terminals with a multimeter (at the ambient temperature 68°F [20°C]).
Normal
1182.5 ± 83 Ω
OCH800A_93
B C
X
1
X
2
3
Y
Y
F G
Outdoor controller board DIP SW9-2
OFF
ON
Normal Abnormal
160 to 410 kΩ Open or short
4.3 to 9.6 kΩ
39 to 105 kΩ
1
2
3
4
5
6
7
Normal Abnormal
1.3 ± 0.06 MΩ Open or short
(Short, for 7 - 4 and
Open
5 - 4)
220 ± 22 kΩ
Open
Abnormal
Open or short
Abnormal
Open or short
Abnormal
Open or short
A: Remote control panel
B: Relay circuit
D
C: External input adapter (PAC-SC36NA-E)
CN3D
D: Outdoor unit control board
1
E: Relay power supply
3
F: Procure locally
G: Max. 10 m [32 ft]
SW1: Switch
SW2: Switch
X, Y: Relay (contact rating: ≥ 0.1 A. 15 VDC, min. applicable load: ≤ 1 mA)
SW1 SW2
Cooling
OFF OFF Normal
ON OFF Silent mode
OFF OFF 100% (Normal)
ON OFF 75%
ON ON 50%
OFF ON 0% (Stop)
Function
Heating
Normal
Silent mode