Siemens SDV-4A Instruction Manual page 43

Overhaul
Troubleshooting (continued)
Problem
Nuisance or false close
Circuit breaker will not trip
Nuisance or false trip
Symptoms
Electrical problem
Mechanical problem
Tripping coil, or solenoid (52T)
does not energize. There is no
tripping sound.
Tripping coil (52T) energizes.
No tripping sound is heard, and
breaker contacts do not open
(i.e., they remain closed).
Tripping coil (52T) energizes.
Tripping sound is heard, but
breaker contacts do not open.
Electrical problem
Mechanical problem
Possible Causes and Remedies
1. Nuisance or false closing signal
to TB4. Check relay logic.
Correct as required.
2. Closing coil (52SRC) terminal
2 is shorted to ground. Check to
determine if problem is in
wiring or coil. Correct as
required.
1. Mechanical failure of operating
mechanism. Check and contact
factory or authorized service
shop.
1. Secondary control power is
de-energized or control power
fuses are blown. Correct as
indicated.
2. Damage to wiring, terminals or
connectors. Check and repair as
necessary.
3. No tripping signal to TB7.
Check for continuity and correct
relay logic.
4. Failure of trip coil (52T).
Check and replace if necessary.
5. Auxiliary switch NO contacts
1-2 or 5-6 are open when
breaker is closed. Check linkage
and switch. Replace or adjust
as necessary.
1. Failure of tripping spring or
its mechanical linkage.
Check and replace if required.
1. Mechanical failure of operating
mechanism. Check and contact
factory or authorized service
shop.
2. One or more of the vacuum
interrupters are held closed.
Check and replace as necessary.
1. Tripping signal remains
energized on TB7. Check for
improper relay logic.
1. Mechanical failure of operating
mechanism. Check and contact
factory or authorized service
shop.
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