Yaskawa VCD 723 - Manual (Page 79)

4 Troubleshooting/Maintenance
73
9/15/93
RESISTANCE TEST FOR 3Ø CONVERTER MODULES (BRIDGE RECT)
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.
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Diode and Transistor Module Resistance Test
Diode and
Transistor
Module
Resistance Test
Measure the resistance across the module terminals with a volt-ohm meter. Set
the meter at the X1 range. The measured resistance should be within the values
listed in Table 10.
+ – NORMAL ABNORMAL
READING READING
ON ON (OHMS) (OHMS)
L1 P
L2 P
L3 P 10 to 50 0 or INFINITE
N L1
N L2
N L3
+ – NORMAL ABNORMAL
READING READING
ON ON (OHMS) (OHMS)
+ – NORMAL ABNORMAL
READING READING
ON ON (OHMS) (OHMS)
L1 N
L2 N
L3 N INFINITE LESS THAN
P L1 1M
P L2
P L3
P N MAGNITUDE 0 or INFINITE
OF CAP
CHARGE TO
INFINITE
+ – NORMAL ABNORMAL
READING READING
ON ON (OHMS) (OHMS)
▲ ▲ ▲
▲ ▲ ▲
L1
L2
L3
P +
N –
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Table 10. Diode Module Resistances
Diode Module