Siemens 38-3AH3 38 kV instruction manual Closing

Vacuum interrupter/ operator

Figure 21: Operator sequential operation diagram

Closing	Closed
	voltage applied.	Anti-pumping feature (52Y) assures a continuously applied closing command does not
		cause the circuit breaker to reclose automatically after it has tripped out on a fault.

	Undervoltage device		Spring-charge motor								Continuous
	27 picks up.		(88.0) energized.
											closing command.
			Closing spring is fully
			charged.
											Close coil (52SRC)
											unlatches the closing
	LS21 and LS22		L3 opens in series				LS4 closes to signal			LS9 closes close	spring and the circuit
	operate to de-		with anti-pump relay				closing spring is			circuit only when	breaker closes.
	energize spring-		(52Y).				charged.			closing spring is fully
	charging motor.									charged.
											Motor cutoff
											switches LS21, LS22
		circuit			circuit						and LS3 are closed
											because the closing
		breaker is			breaker is
	No action! Open 52b						Close coil is actuated				spring is discharged.
	in series with close	closed.			open.		through the closed
	coil (52SRC) blocks			Closing			52b contacts and the
				command
	closing spring-						two normally closed				Before the spring-
				when
	release.						contacts of the anti-				charge motor has
					closing		pump relay (52Y).				recharged the
											closing spring and
					spring is not
											opened LS3, anti-
					charged.
											pump relay (52Y)
											picks up and seals in.
			No action! Anti-				The closing spring is			The opening spring
			pump relay (52Y)				unlatched.			is charged.
			picks up through the
			closed LS3 contact								The anti-pump relay
											(52Y) opens two
			and opens.
											contacts in series
											with the close coil
	52a contacts in		Circuit breaker				The circuit breaker			LS21 and LS22 close	(52SRC).
	series with the trip		auxiliary contacts				closes.			to energize motor
	coil (52T) close to		52a and 52b change							(88). LS3 closes and
	enable a trip		state.							LS4 opens to cancel
											The close coil
	opertion.									closing spring signal.
											(52SRC) is now
											blocked and cannot
											be activated until
	Rapid auto-reclosing. The closing spring is automatically recharged as described above.										springs are fully-
	Therefore, when the circuit breaker is closed both of its springs are charged. The closing spring										charged and close
	charges the opening spring during closing. As a result, the circuit breaker is capable of an										command is
	O-0.3s-CO-3 min-CO operating cycle. The dashed line shows the operating sequence initiated by										removed.
	the closing command.
Tripping								Trip
							command.
	Trip coil (52T) can		Undervoltage device (27) is						Undervoltage device (27) is activated		Secondary shunt-
	only be activated		activated by opening a NC						by closing NO contact, shorting the		release (dual-trip)
	when in series		contact in series with 27 or by						27 coil. The NO contact is only		function activated by
	connected 52a		loss or reduction of tripping						effective with the circuit breaker		remote trip
	contact is closed.		voltage.1						closed. Resistor required.1		command contact
											NO.1
	Trip coil (52T)					Undervoltage device					Secondary release
	unlatches the					27 unlatches the					unlatches the
	opening spring.					opening spring.1					opening spring.1

Circuit breaker trips.

Footnote:

1Optional items.

28