Transistor module – Yaskawa VCD 723 User Manual
Page 80
4
Troubleshooting/Maintenance
74
Diode and Transistor Module Resistance Test
9/15/93
Measure the resistance across the module terminals with a volt-ohm meter. Set
the meter to the X1 range. The measured resistance should be within the values
listed in Table 11.
Transistor
Module
+
–
NORMAL
ABNORMAL
READING
READING
ON
ON
(OHMS)
(OHMS)
P+
T1
P+
T2
P+
T3
T1
N-
INFINITE
0
T2
N-
T3
N-
T1
P+
T2
P+
T3
P+
5** to 50
0 or INFINITE
N-
T1
N-
T2
N-
T3
+
–
NORMAL
ABNORMAL
READING
READING
ON
ON
(OHMS)
(OHMS)
+
–
NORMAL
ABNORMAL
READING
READING
ON
ON
(OHMS)
(OHMS)
G1A
T1
G1B
T2
LESS
G1C
T3
INFINITE
G2A
N-
THAN
G2B
N-
G2C
N-
1M
T1
G1A
T2
G1B
LESS
T3
G1C
INFINITE
N-
G2A
THAN
N-
G2B
N-
G2C
1M
+
–
NORMAL
ABNORMAL
READING
READING
ON
ON
(OHMS)
(OHMS)
Table 11. Transistor Module Resistances
▲
▲
▲
▲
▲
▲
●
●
●
●
●
●
●
G1A
E1A
E1B
E1C
C2A
C2B
C2C
G1B
G1C
G2A
E2A
E2B
E2C
G2B
G2C
C1A
C1B
C1C
T1 (A
φ)
T2 (B
φ
)
T3 (C
φ
)
P +
N –
RESISTANCE TEST FOR 3Ø TRANSISTOR MODULES
VOM RESISTANCE SCALE R x 1
+ IS THE POSITIVE POLARITY LEAD*
- IS THE NEGATIVE POLARITY LEAD
*THE VOM RED LEAD IS NOT NECESSARILY THE POSITIVE POTENTIAL IN THE RESISTANCE MODE.
FOR THESE TESTS THE + LEAD REFERS TO THE POSITIVE POTENTIAL. MAKE SURE YOU KNOW
WHICH POLARITY YOU HAVE ON YOUR VOM.
**OR 0.3 TO 0.7 ON DIGITAL METER SET TO DIODE DROP SCALE.