WEG VBWC Series, Installation,Operation And Maintenance Instruction

Page: 23 / 88

www.weg.net
Vacuum Circuit Breaker | 23
Check Item Check list Method Solução Frequency
Contact resistance
of main circuit
Measure a contact resistance of
main circuit after drawing out
the VCB.
- It must be less than 120% of
final inspection report value
- The variation resistance
between phases must be less
than 25%
The voltage drop
method (DC 100A)
- Measure with
inserting the same
size copper bar
(make a jig for
measuring if
necessary)
1. Dismantle the
contactors
2. Clean the
discoloration,
corrosion or heated
parts of arc
3. Clean the contactor
surface after removing
foreign substances
4. Apply specified
grease
*Specification:
HITALUBE280G
Annually
Temperature rising
Check the temp. rising of
contacted and connection parts
*The max. available limit of
temp. rising
- Contacted part: 65K
- Connected part: 75K
(K: Temperature rise)
Visual
Infrared camera
Carry out a close
inspection
As occasion
demands
Table 10.3: Items of periodic inspection (1).
Notes:
1. Apply specified grease after replacement. (specification: HITALUBE280G)
2. Measure the contact resistance of main circuit with no-load mechanical operating test after replacement. The measured values should
be compared with the measured values before replacement and they should be put on record.
3. If there are traces of arc when replacing contactors, the terminals should be replaced . In case that there aren’t any traces, wipe clean
on terminal surface.
10.4 SPECIAL INSPECTION
Make a special inspection in case of situation as Table 8.4.
N
o
Inspection item Inspection method
1 When interrupting short-circuit(fault) current several times Check wearing contacts of vacuum interrupter
2 In case of appearing a abnormal situation at service operation Check defective parts
Table 10.4: Special inspection.