Hitachi RCD-2.5FSG1, Service Manual

Page: 122 / 384

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TROUBLESHOOTING
(2) Checking Procedures Transistor Module (In Case of 5 to 20HP)
Outer Appearance and Internal Circuit of Transistor Module
[Case 1]
[Case 2 and 3]
Remove all the terminals of the transistor module before check.
If items (a) to (e) are performed and the results are satisfactory, the transistor module is normal.
Measure it under 1 k
Ω
range of a tester. Do not use a digital tester.
(a) By touching the + side of the tester to the P terminal
of transistor module and the - side of tester to U, V
and W of transistor module, measure the resistance.
If all the resistances are from 1 to 5 k
Ω
, it is normal.
(b) By touching the - side of the tester to the P terminal
of transistor module and the + side of tester to U, V
and W of transistor module, measure the resistance.
If all the resistances are greater than 100 k
Ω
, it is
normal.
P
B
N
U
V
W
P
B
N
U
V
W
U
V
W
N
B P
Vcc Fo In GND
Out
S1
GND
V
UP
U
Fo
U
P
V
UPC
Vcc Fo In GND
Out
S1
GND
V
VP
V
Fo
V
P
V
VPC
Vcc Fo In GND
Out
S1
GND
V
WP
W
Fo
W
P
V
WPC
Vcc Fo In GND
Out
S1
GND
U
N
Vcc Fo In GND
Out
S1
GND
W
N
Vcc Fo In GND
Out
S1
GND
V
N1
W
N
V
NC
Vcc Fo In GND
Out
S1
GND
B
r
F
o
TEMP
Th
P U V W N B
1
4
7
10
16
U
V
W
B P N
Pre-Dr
iv
er
Pre-Dr
iv
er
Pre-Dr
iv
er
Pre-Dr
iv
er
Pre-Dr
iv
er
Pre-Dr
iv
er
Ov
er Heating
Protection Circuit
VccU
P U V
W
VinU GNDU VccV VinV GND
V
VccW VinW GND
W
Vcc VinX GND VinY VinZ ALM
NC
B
N
NC
Vz Vz Vz
Vz Vz Vz
3 2 1 6 5 4 9 8 7
11 13 10 14 15 12 16
1.5k
Ω