46
Table 9: Troubleshooting (continued)
Problem
Symptoms
Possible causes and remedies
Nuisance or false close
Electrical problem
1. Nuisance or false closing signal to secondary
disconnect multi-pin plug contact. Check
protective relay logic. Correct as required.
2. (Stored-energy) closing coil (52SRC) terminal
A2 is shorted-to-ground. Check to determine
if problems are in wiring or coil. Correct as
required.
Mechanical problem
1. Mechanical failure of operating mechanism.
Check and contact the factory or Siemens
field service at +1 (800) 347-6659 or +1
(919) 365-2200 outside the U.S.
Circuit breaker will not trip
(Stored-energy) tripping coil or solenoid (52T)
does not energize. There is no tripping sound.
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 multi-pin plug contact
C2. Check for continuity and correct
protective relay logic.
4. Secondary multi-pin plug contacts C2 or D2
are not engaging. Check and replace if
required.
5. Failure of trip coil (52T). Check and replace if
necessary.
6. Auxiliary switch 52a NO contacts 23 to 24 or
33 to 34 are open when circuit breaker is
closed. Check linkage and switch. Replace or
adjust as necessary.
(Stored-energy) tripping coil (52T) energizes. No
tripping sound is heard, and circuit breaker
contacts do not open. In other words, they
remain closed.
1. Failure of tripping spring or its mechanical
linkage. Check and replace if required.
(Stored-energy) tripping coil (52T) energizes.
Tripping sound is heard, but circuit breaker
contacts do not open.
1. Mechanical failure of operating mechanism.
Check and contact the factory or Siemens
field service at +1 (800) 347-6659 or +1
(919) 365-2200 outside the U.S.
2. One or more of the vacuum interrupters are
held closed. Check and replace as necessary.
Nuisance or false trip
Electrical problem
1. Tripping signal remains energized on
secondary multi-pin plug contact C2.
2. Check for improper protective relay logic.
Mechanical problem
1. Mechanical failure of operating mechanism.
Check and contact the factory or Siemens
field service at +1 (800) 347-6659 or +1
(919) 365-2200 outside the U.S.
Summary of Contents for SDV7
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