Siemens 38-3AH3 38 kV instruction manual Racking interlocks Closed circuit breaker interlock

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The two plates are mounted in alignment and must pass through each other in order for the circuit-breaker vehicle to enter the drawout compartment. The interlock is coded to test rated voltage, as well as interrupting and continuous current ratings. The circuit breaker must equal or exceed all of the cubicle ratings in order to enter the compartment.

2.Racking interlocks

A.CLOSED circuit breaker interlock

Figure 32: Circuit-breaker interlocks and ground disconnect on page 33 shows the location of the CLOSED circuit-breaker interlock-plunger on the circuit-breaker frame.

The purpose of this interlock is to positively block circuit-breaker racking-operations whenever the circuit breaker is CLOSED. The plunger is coupled to the jack shaft as seen in Figure 15: Stored-energy operating mechanism, item 63 on page 20. When the jack shaft rotates to close, the interlock plunger is driven straight downward beneath the frame of the circuit breaker. The downward projecting plunger blocks racking operation when the circuit breaker is CLOSED.

Figure 33: Circuit-breaker compartment (MOC/TOC switch cover plate removed for photo) on page 34 shows the racking mechanism located on the floor in the center of the circuit breaker compartment. Note the two "wing- like" elements that project from the left side of the racking mechanism. The CLOSED circuit breaker interlock plunger, when down (circuit breaker CLOSED), falls behind the front wing in the TEST position and behind the rear wing in the CONNECT position.

Vacuum interrupter/ operator

Trip-free

 

 

 

mechanical-

Trip-free

Spring-dump

Spring-dump

interlock switch

interlock

interlock

tube

 

 

 

 

Figure 34: Interlock mechanisms on the type 38-3AH3 vacuum circuit breaker

The wings are coupled to the element of the racking mechanism that shrouds the racking screw. This shroud must be moved rearward to insert the racking-crank socket in order to engage the racking shaft. With the plunger down (circuit breaker CLOSED), the wings and shroud cannot be moved and thus racking is blocked.

B. Trip-free interlock

Figure 32: Circuit-breaker interlocks and ground disconnect on page 33 shows the trip-free interlock. This interlock is a plunger with a roller on the lower end. The plunger roller tracks the shape of the cam profiles on the racking mechanism in the switchgear (refer to Figure 33: Circuit-breaker compartment (MOC/ TOC switch cover plate removed for photo) on page 34).

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Contents Answers for energy Qualified person Table of contents Introduction Signal words Hazardous ProceduresIntroduction Introduction Field service operation and warranty issuesReceiving, handling and storage Introduction Receiving procedureShipping damage claims Receiving, handling and storage Handling procedureIndoor storage Storage procedureOutdoor storage Space heatingInspections, checks and tests without control power Installation checks and functional testsDe-energizing control power in switchgear Installation checks and functional tests Type 38-3AH3 vacuum circuit breaker racking Racking crank engagement procedureManual-spring charging check Physical inspectionsSplit-plug jumper connected to circuit breaker Final mechanical inspections without control powerVacuum interrupter/ operator Vacuum interrupters Vacuum interrupter/ operatorPrimary disconnects Phase barriersStored-energy operating mechanism 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 Shock absorber Capacitor-trip deviceSecondary disconnect 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 lubricationChecks of the primary power path Removal from switchgearCleanliness check 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 tests Vacuum-integrity check using dielectric testHigh-potential test voltages 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

38-3AH3 38 kV specifications

The Siemens 38-3AH3 is a high-voltage circuit breaker designed for medium voltage applications, particularly in substations and industrial environments. This device operates at a voltage level of 38 kV, showcasing Siemens' commitment to innovation and reliability in electrical engineering.

One of the main features of the Siemens 38-3AH3 is its advanced interruption technology, which employs the proven hybrid design combining both gas-insulated and air-insulated technologies. This hybrid approach not only enhances the breaker's performance and reliability but also minimizes its footprint, making it an ideal choice for space-constrained environments.

The Siemens 38-3AH3 uses vacuum interruption technology, allowing for efficient switching with minimal wear and tear. The vacuum interrupters are highly reliable and provide excellent performance under various operating conditions. This technology ensures that the circuit breaker can handle short circuits and overloads effectively, thus protecting the entire electrical system.

Additionally, the Siemens 38-3AH3 incorporates intelligent monitoring systems. These digital technologies provide real-time data on breaker status, operational performance, and maintenance needs. This predictive maintenance capability helps operators to identify potential issues before they develop into significant problems, ultimately leading to reduced downtime and maintenance costs.

Another notable characteristic of the Siemens 38-3AH3 is its high insulation strength. Thanks to its robust design and development, this circuit breaker can withstand adverse environmental conditions, making it suitable for use in diverse geographical locations and climates. Its components are designed to resist contamination and corrosion, ensuring long-term reliability.

The Siemens 38-3AH3 also offers enhanced safety features. It includes protective relays and automatic fault detection systems that isolate faults quickly, preventing damage to downstream equipment. Furthermore, the design allows for easy maintenance, with components that are accessible without the need for extensive disassembly.

In summary, the Siemens 38-3AH3 38 kV circuit breaker is a leading solution in high-voltage protection and control, characterized by its advanced interruption technology, integrated monitoring systems, high insulation strength, and user-friendly maintenance features. Its innovative design and engineering make it a trusted choice for utilities and industrial facilities aiming to enhance the reliability and safety of their electrical systems.
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