Siemens vacuum circuit breaker 38-3AH3 38 kV - Manual (Page 60)

Maintenance and
troubleshooting
Problem Symptoms Possible causes and remedies
Circuit breaker fails to close. Closing spring will not automatically charge. 1. Secondary control circuit is de-energized or
control circuit fuses are blown. Check and
energize or replace if necessary.
2. Secondary disconnect contacts 15 or 16 are
not engaging. Check and replace if required.
3. Damage to wiring, terminals or connectors.
Check and repair as necessary.
4. Failure of charging motor (88.0). Replace if
required.
5. Motor cut-off switch LS21 or LS22 fails to
operate. Replace if necessary.
6. Mechanical failure of operating mechanism.
Check and contact regional service centers,
the factory or telephone Siemens field
service at +1 (800) 347-6659 or +1 (919)
365-2200 outside the U.S.
Closing springs
charge, but circuit
breaker does not close. Closing coil or solenoid
(52SRC) fails to
energize. No sound of
circuit breaker closing. 1. Secondary control circuit de-energized or
control circuit fuses blown. Correct as
indicated.
2. No closing signal to secondary disconnect
pin 13. Check for continuity and correct
protective relay logic.
3. Secondary disconnect contacts 13 or 15 are
not engaging. Check and correct as
required.
4. Failure of anti-pump relay (52Y) contacts 21
to 22, 31 to 32 or 13 to 14. Check and
replace as required.
5. Failure of close coil (solenoid) (52SRC).
Check and replace as required.
6. Auxiliary switch NC contacts 41 to 42 are
open when circuit breaker contacts are
open. Check linkage and switch. Replace or
adjust as necessary.
7. Spring-charged switch LS9 NO contacts
remain open after springs are charged.
Check and replace as required.
Closing coil energizes.
Sound of circuit
breaker closing is heard
but circuit breaker
contacts do not close. 1. Mechanical failure of operating mechanism.
Check and contact regional service centers,
the factory or telephone Siemens field
service at +1 (800) 347-6659 or +1 (919)
365-2200 outside the U.S.
Table 7: Troubleshooting
60