Daikin VRV RXYQ72-384XAYCA, Service Manual

Page: 369 / 419

SiUS342004EB Check
Part 6 Service Diagnosis 362
4.4 Power Transistor Check
CHECK 4
Perform the following procedures prior to check.
(1) Power OFF.
(2) Remove all the wiring connected to the PCB where power transistors are mounted on.
PCB and Circuit Diagram
Preparation
h
Multimeter  Prepare the analog type of multimeter.
For the digital type of multimeter, those with diode
check function are available for the checking.
Point of Measurement and Judgment Criteria

Turn OFF the power supply. Then, after a lapse of 10 minutes or more, make measurement of
resistance.
No.
Measuring
point
When using the analog type of multimeter,
make measurement in resistance
measurement mode in the x1 k

range.
When using the digital type of multimeter,
make measurement in diode check mode
( ).
+ – Judgement Criteria Remarks Judgement Criteria Remarks
1 P31 U
2 ~ 30 k  – 1.2 V or more
Due to condenser
charge and so on,
resistance
measurement may
require some time.
2 P31 V
3 P31 W
4 U P31
15 k  and more
(including  )
Due to condenser
charge and so on,
resistance
measurement may
require some time.
0.3 ~ 0.7 V –
5 V P31
6 W P31
7 N31 U
8 N31 V
9 N31 W
10 U N31
2 ~ 30 k

– 1.2 V or more
Due to condenser
charge and so on,
resistance
measurement may
require some time.
11 V N31
12 W N31
P11 P21
IGBT
U V W
L1B
L2B
L3B
DM
P31
N31
P31
U V W
N31