Troubleshooting For Leakage Operation Portion; Troubleshooting Of Accessories - Mitsubishi Electric C Series Handling And Maintenance

5.2 Troubleshooting for leakage operation portion

Trouble
Operates simultaneously
with closing (such operation
Trouble-
of leakage mechanism as
some
popping-out of the leakage
action
display button)
Operates during use
Leakage operation and the
Abnormal
like by test button, but no
operation
display
No
Depressing the test button
operation
does not lead to operation

5.3 Troubleshooting of accessories

Trouble
Operation
disabled
NFM/NVM
(electric operation
device)
Continuous idling
One turn of idling
when closing
Closing disabled
UVT
(undervoltage tripping
No tripping even
device)
with no voltage
SHT (voltage tripping
No tripping action
device)
AL (alarm switch),
AX (auxiliary switch),
EAL (earth-leakage
Malfunction
alarm, switch),
MG (Insulation switch)
PAL (pre-alarm)
Cause
Too long a wire and too large a ground electrostatic
capacity causes the leak current to flow
Normal operation due to leak current
Refer to 5.4
Poor lamp or its end of service life
Display button does not come out due to poor
adjustment
Trouble in electronic circuit
No voltage applied
Poor continuity of contact
Cause
Too low a capacity of the
wire of operational circuit
Voltage drop of
operational power supply
Too low a capacity of the
operational power supply
Excessive continuous
Burnt resistor/motor
operation
Erroneous wiring
Erroneous voltage applied
Operation of ON and OFF circuits at the same
time or erroneous manipulation
Self-sustaining auxiliary switch contact to be
used for automatic resetting
Voltage tripping in OFF state or tripping by
undervoltage
The circuit-breaker proper has automatically
cut off and tripped
Erroneous frequency or voltage applied
No pulling Too large a voltage drop
Trouble in circuit-breaker tripping mechanism
Operational voltage drop
Insufficient voltage
Erroneous voltage applied
Continous excitation
of coil
Continuous excitation under a voltage
Coil burnt out
inferior to the operating voltage
Poor auxiliary contact
for prevention of burning
Abnormal voltage applied
Poor contact due to overcurrent
Erroneous wiring
Erroneous wiring
when installing
Erroneous selection
Microload
Loosened attaching
Insufficient tightening
screws
Vibration during transportation
Countermeasure
Rated sensitivity current to be changed, or
ELCB to be installed near load
Leak point to be repaired
To be replaced by new one
To be returned for repairing
To be replaced by new one
Apply specified voltage
Remove foreign matter on the contact
Countermeasure
Increase the diameter of the wire
Improve the operational power supply
To be returned for repairing (replacement of
resister/motor)
Regularize the wiring
Regular operational voltage to be applied
Push button to be provided with interlock
The contact for automatic resetting to be used
as that for alarm switch
OFF operation once to reset and ON operation
again
Power supply to be improved
Voltage to be improved
To be returned for repairing
Power supply to be improved
Power supply to be improved
To be returned for repairing (replacement of
coil, auxiliary contact to be provided for
protection from burning)
To be returned for repairing (replacement of
coil), power supply to be improved
To be returned for repairing (replacement of
coil, contact to be repaired)
To be returned for repairing (replacement of coil)
To be returned for repairing
Regular wiring to be made referring to the
name plate
To be returned for repairing (to be replaced
with that for microload)
To be returned for repairing (re-adjustment)
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