Power Transistor Check - Daikin VRV RXYQ72-384XAYCA Service Manual

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