Siemens 38-3AH3 38 kV Instruction Manual

Contents

Vacuum interrupter/operatorFigure 21: Operator sequential operation diagramClosedvoltage applied.Undervoltage device27 picks up.Spring-charge motor(88.0) energized.L3 opens in serieswith anti-pump relay(52Y).LS21 and LS22operate to de-energize spring-charging motor.LS4 closes to signalclosing spring ischarged.LS9 closes closecircuit only whenclosing spring is fullycharged.Closing spring is fullycharged.No action! Open 52bin series with closecoil (52SRC) blocksclosing spring-release.Close coil is actuatedthrough the closed52b contacts and thetwo normally closedcontacts of the anti-pump relay (52Y).Closingcommandwhencircuitbreaker isclosed.circuitbreaker isopen.No action! Anti-pump relay (52Y)picks up through theclosed LS3 contactand opens.closingspring is notcharged.The closing spring isunlatched.The opening springis charged.Circuit breakerauxiliary contacts52a and 52b changestate.The circuit breakercloses.LS21 and LS22 closeto energize motor(88). LS3 closes andLS4 opens to cancelclosing spring signal.52a contacts inseries with the tripcoil (52T) close toenable a tripopertion.Continuousclosing command.Close coil (52SRC)unlatches the closingspring and the circuitbreaker closes.Motor cutoffswitches LS21, LS22and LS3 are closedbecause the closingspring is discharged.Before the spring-charge motor hasrecharged theclosing spring andopened LS3, anti-pump relay (52Y)picks up and seals in.The anti-pump relay(52Y) opens twocontacts in serieswith the close coil(52SRC).The close coil(52SRC) is nowblocked and cannotbe activated untilsprings are fully-charged and closecommand isremoved.Rapid auto-reclosing. The closing spring is automatically recharged as described above.Therefore, when the circuit breaker is closed both of its springs are charged. The closing springcharges the opening spring during closing. As a result, the circuit breaker is capable of anO-0.3s-CO-3 min-CO operating cycle. The dashed line shows the operating sequence initiated bythe closing command.ClosingTrippingAnti-pumping feature (52Y) assures a continuously applied closing command does notcause the circuit breaker to reclose automatically after it has tripped out on a fault.Tripcommand.Trip coil (52T) canonly be activatedwhen in seriesconnected 52acontact is closed.Undervoltage device (27) isactivated by opening a NCcontact in series with 27 or byloss or reduction of trippingvoltage. 1Secondary shunt-release (dual-trip)function activated byremote tripcommand contactNO. 1Undervoltage device (27) is activatedby closing NO contact, shorting the27 coil. The NO contact is onlyeffective with the circuit breakerclosed. Resistor required. 1Undervoltage device27 unlatches theopening spring. 1Circuit breaker trips.Secondary releaseunlatches theopening spring. 1Trip coil (52T)unlatches theopening spring.Footnote:1 Optional items.28