Siemens 38-3AH3 38 kV instruction manual Interrupter/operator module, Construction

Page 17

Vacuum interrupter/ operator

The vacuum circuit breaker consists of two sub-assemblies. The "interrupter/operator" module is a unitized assembly of the three vacuum interrupters, primary insulators and operating mechanism. The second module, the "vehicle", is the supporting drawout-structure module for the operating mechanism. The vehicle provides primary-stud extensions, closed circuit-breaker racking interlocks, closing spring discharge feature and other requirements needed to ensure safe and reliable use during racking and during operation. These two sub-assemblies will be separately described.

Interrupter/operator module

The interrupter/operator module consists of the three poles, each with its vacuum interrupter and primary insulators, mounted on the common motor or hand- charged spring-stored energy-operating- mechanism housing. This module is shown in Figure 12: Interrupting/operating mechanism module (shown with outer- phase barrier removed).

Construction

Refer to Figure 12: Interrupting/operating mechanism module (shown with outer- phase barrier removed) on page 17, Figure

13:Operating mechanism controls and indicators on page 18, Figure 14: Type 38- 3AH3 vacuum circuit breaker pole section on page 19 and Figure 15: Stored-energy operating mechanism on page 20.

Each of the circuit breaker poles is fixed to the rear of the operating-mechanism housing (60.0) by two cast-resin insulators (16.0).

The insulators also connect to the upper (20.0) and lower (40.0) pole-supports that in turn support the ends of the vacuum interrupter (30.0). Primary stud-extensions are attached directly to the upper pole- support (20.0) and lower terminal (29.0).

The energy-storing mechanism and all the control and actuating devices are installed in the mechanism housing (60.0).

The mechanism is of the spring stored- energy type and is mechanically and electrically trip-free.

Figure 11: Type 38-3AH3 vacuum circuit breaker with inter-phase and outer-phase barriers installed

16.020.0

60.0

30.0

29.0

		40.0
16.0	- Insulator	30.0	- Vacuum interrupter
20.0	- Pole head	40.0	- Pole bottom
29.0	- Lower connection terminal	60.0	- Operator housing

Figure 12: Interrupter/operating mechanism module (shown with outer-phase barrier removed)

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Image 17

Contents

Answers for energy Qualified person Table of contents Introduction Signal words Hazardous ProceduresIntroduction Introduction Field service operation and warranty issuesShipping damage claims Introduction Receiving procedureReceiving, handling and storage Receiving, handling and storage Handling procedureIndoor storage Storage procedureOutdoor storage Space heatingDe-energizing control power in switchgear Installation checks and functional testsInspections, checks and tests without control power Installation checks and functional tests Type 38-3AH3 vacuum circuit breaker racking Racking crank engagement procedureManual-spring charging check Physical inspections Split-plug jumper connected to circuit breaker Final mechanical inspections without control powerVacuum interrupter/ operator Vacuum interrupters Vacuum interrupter/ operatorStored-energy operating mechanism Phase barriersPrimary disconnects Construction Interrupter/operator moduleSwitching operation Current-path assemblyCircuit-breaker pole Vacuum interrupterType 38-3AH3 vacuum circuit breaker pole section Stored-energy operating mechanism Mode of operation Auxiliary switchOperating mechanism Indirect releases tripping coilsUse of manual-spring operation crank ClosingOpening Trip-free functionalityRapid auto-reclosing Manual operation62.2 62.5.2 50.3.1 53.0 Pawl roller 62.5.2 Close-latch pawl Vacuum interrupter/ operator Discharged Closing Standard Undervoltage optional Indirect releases dual-trip orSecondary shunt release optional 54.2Position a locked Secondary disconnect Capacitor-trip deviceShock absorber Truck-operated cell TOC switch Mechanism-operated cell MOC switch optionalShutter-operating linkage Secondary disconnect Shutters Rating interlock Trip-free interlockCircuit-breaker frame Ground disconnectVehicle function and operational interlocks Racking mechanismAlignment Interlocks Circuit breaker racking-interlocksRacking interlocks Closed circuit breaker interlock Automatic closing-spring energy release Trip-free interlock position mechanical interlock Introduction and maintenance intervals MaintenanceRecommended hand tools MaintenanceInspection items and tests Recommended maintenance and lubricationCleanliness check Removal from switchgearChecks of the primary power path Circuit Number Maintenance and lubricationInspection of primary disconnects Checks of the stored-energy operator mechanismTypical for all three-phases Manual-spring charging and contact- erosion checks Fastener checkAutomatic spring-charging check control power required Wiring and terminals checkElectrical-control checks Secondary-disconnect checkTypical vacuum interrupter contact curve Vacuum-interrupter mechanical check Spring-charging motor checksHigh-potential test voltages Vacuum-integrity check using dielectric testHigh-potential tests Voltage Frequency withstand Field-test voltageContinuous Contact Inspection and cleaning of circuit- breaker insulationRating a Functional testsOverhaul Replacement at overhaulCircuit-breaker overhaul Circuit breaker Number TypeOverhaul Vacuum interrupter replacementSetting Vacuum interrupter replacement illustration Overhaul Hydraulic shock absorber Checking the contact stroke Open the circuit breakerSub-assembly Inspect for Maintenance and troubleshootingProblem Symptoms Possible causes and remedies Maintenance and troubleshootingClosed Appendix Appendix Maximum design voltage Permissible tripping delay YValues Voltage Voltage range factor K3 Insulation Withstand Voltage levels Lightning-impulse BILLevels Voltage levels Lightning-impulse BIL Rated Maximum design voltageRated Continuous4 Short-circuit at rated maximum design voltage I5, 6Remarks Appendix