Eaton MDN-408 Instructions For Installation, Operation And Maintenance page 78

Instruction Book
Page 68 Effective: May 2006
Table 7.1 Circuit Breaker Troubleshooting Guide (continued from previous page)
Symptom
Circuit breaker cannot
be opened remotely, but
can be opened locally
Circuit breaker cannot
be opened locally
Circuit breaker makes
no attempt to close with
either local (manual) or
remote controls; springs
do not discharge
Probable Cause
Shunt trip control signal
absent or too low
Shunt trip is faulty or
improperly installed
Secondary contact wiring
problem
OPEN pushbutton locked
Faulty mechanism or main
contacts welded
Closing spring not fully
charged (check SPRING
CHARGED indicator)
If equipped with undervoltage
release, undervoltage release
is not energized or is faulty
Circuit breaker locked in
OPEN position
Drawout position interlock
is operating; levering screw
Circuit breaker interlocked
with another circuit breaker
or device
For more information visit: www.EatonElectrical.com
Corrective Actions
Check supply voltage exceeds
70% of rated voltage when
signal is applied to shunt trip
Remove front cover; check
voltage supplied to shunt
trip; make sure shunt trip is
seated and retainer snapped
into place. Check for shunt
trip motion; replace shunt
trip if faulty
Make sure electrical pin and
socket connectors are properly
seated in molded plug. Verify
proper wiring
Remove lock
Contact Cutler-Hammer
service center
Charge spring manually; check
voltage to electrical operator;
replace electrical operator if
faulty
Unplug undervoltage release
from mounting deck and retry
closing operation; if OK, check
voltage supply to undervoltage
release (>85%); replace under-
voltage release if faulty
Check reason for lock
Make sure that circuit breaker is
at a position that permits closure;
door is open check that shutter
(door) over the levering screw
is fully closed
Check for presence of an
interlocking scheme (cable
interlock or key interlock);
check to see if interlocked
circuit breaker is CLOSED
I.B. 2C12060H08