Siemens 38-3AH3 38 kV instruction manual Closed

Maintenance and troubleshooting

Table 7: Troubleshooting (continued)

Problem

Symptoms

Possible causes and remedies

Nuisance or false close	Electrical problem	1.	Nuisance or false closing signal to secondary
			disconnect 13. Check protective relay logic.
			Correct as required.
		2.	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 regional service centers,
			the factory or telephone Siemens field service
			at +1 (800) 347-6659 or +1 (919) 365-2200
			outside the U.S.
Circuit breaker will not trip	Tripping coil or solenoid (52T) does not	1.	Secondary control power is de-energized or
	energize. There is no tripping sound.		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 secondary disconnect
			contact 1. Check for continuity and correct
			protective relay logic.
		4.	Secondary disconnect contacts 1 or 2 are not
			engaging. Check and replace if required.
		5.	Failure of trip coil (52T). Check and replace if
			necessary.
		6.	Auxiliary switch 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.
	Tripping coil (52T) energizes. No tripping	1.	Failure of tripping spring or its mechanical
	sound is heard, and circuit breaker contacts		linkage. Check and replace if required.
	do not open. In other words, they remain
	CLOSED.
	Tripping coil (52T) energizes. Tripping sound	1.	Mechanical failure of operating mechanism.
	is heard, but circuit breaker contacts do not		Check and contact regional service centers,
	open.		the factory or telephone 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-disconnect contact.
		2.	Check for improper protective relay logic.
	Mechanical problem	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.

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