Specifications

SiUS12-928_A Check
Service Diagnosis 156
6.1.10 Capacitor Voltage Check
Check No.12 Before this check, be sure to check the main circuit for short circuit.
With the circuit breaker still on, measure the voltage according to the drawing of the model in
question. Be careful never to touch any live parts.
18 class
24/32 class
6.1.11 Power Transistor Check
Check No.13  Never touch any live parts for at least 10 minutes after turning off the circuit breaker.
 If unavoidably necessary to touch a live part, make sure the power transistor's supply voltage is
below 50 V using the tester.
 For the UVW, make measurements at the terminal on the PCB or the relay connector.
Fan motor
lead wire
Four way valve coil
lead wire
Thermistor
lead wire
(Liquid pipe)
Thermistor
lead wire
(Gas pipe)
Thermistor
lead wire
Overload
protector
lead wire
Reactor
lead wire
Compressor
lead wire
TB2
>PS<
TB3
P2 N1
S90 S92 S93
S80
S20 S21 S22
S40
Multimeter
(DC. voltage range)
(Room-C)(Room-B)(Room-A)
Electronic expansion valve coil lead wire
(R11308)
Thermistor lead wire
(Gas pipe)
Thermistor lead wire
(Liquid pipe)
Four way valve coil lead wire
Multimeter
(DC. voltage range)
Reactor lead wire Compressor lead wire
Overload protector lead wire
Thermistor lead wire
Fan motor lead
(R11230)
(Room-D)(Room-C)(Room-B)(Room-A)
Electronic expansion valve coil lead wire
Tester's negative terminal
Power transistor
(+)
UVW
Power transistor
(–)
UVW
Tester's positive terminal UVW
Power transistor
(+)
UVW
Power transistor
(–)
Normal resistance Several kΩ to several MΩ
Abnormal resistance 0 or ∞