KRB-5200h
-31-
9. TROUBLESHOOTING
If a trouble occurs, take appropriate measures according to the following table.
Symptom
Possible cause
Action/remedy
ACB trips open
immediately after closing
operation.
1. Inrush current is too large.
2. A short-circuit occurs
somewhere.
3. There is erroneous connection in
UVT or SHT control circuit.
Review starting method of load, or
change short time-delay trip pick-up
current (I
2
) setting.
Check electrical distribution system.
Check wire connection
Closing operation is
impossible.
1. Voltage is not applied to UVT, or
applied voltage is too low.
2. UVT is defective.
Coil disconnection or layer
short-circuit
Moving core reset
unsuccessfully
OCR controller malfunction
3. SHT is defective.
Moving core reset
unsuccessfully
4. Handle is not reset.
5. Tripping mechanism is out of
order.
Latch worn out
Spring broken or out of order.
Apply voltage of rated voltage x 85 %
or more to UVT.
Replace defective UVT. Consult
Terasaki for advice.
Replace defective SHT.
Reset handle.
Repair tripping mechanism. Consult
Terasaki for advice.
An excessive number of operation
cycles will cause tripping mechanism
to wear out. Replace ACB.
Opening operation is
impossible.
Main contact is welded.
Replace ACB.
Tripping operation is
impossible.
1. OCR is defective.
2. UVT is defective.
Blockage of moving coil
3. UVT or SHT circuit is defective.
4. SHT is defective.
Insufficient stroke of moving
core
Coil disconnection or layer
short-circuit
Anti-burnout switch is
defective.
5. Voltage applied to SHT is too
low.
6. Tripping mechanism is out of
order.
Increase of friction in
mechanism
Corrosion, wear, and/or
deformation of latch and/or
roller
Spring broken or out of position
Replace ACB. Consult Terasaki for
advice.
Replace UVT. Consult Terasaki for
advice.
Check for looseness of wire
connections and switch contacts.
Replace SHT.
Apply voltage of rated voltage x 70%
or more.
Lubricate mechanism to reduce
friction. An excessive number of
operation cycles will cause tripping
mechanism to wear out. Replace
ACB.
Summary of Contents for AME Series
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Page 32: ...KRB 5200h 26 5 3 Operation Characteristic Curves ...
Page 39: ...KRB 5200f ...