Siemens 38-3AH3 38 kV Circuit-breaker pole, Current-path assembly, Vacuum interrupter

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Vacuum interrupter/ operator

 

53.0

55.0

54.0

58.0

 

59.0

 

53.0- Manual close button

54.0- Manual open (trip) button

55.0- CHARGED/DISCHARGED indicator

58.0- OPEN/CLOSED indicator

59.0- Operations counter

Figure 13: Operating mechanism controls and indicators

The OPEN/CLOSED indicator (58.0), CHARGED/DISCHARGED indicator (55.0) and the operations counter (59.0) are located on the front of the mechanism housing (60.0).

Circuit-breaker pole

Refer to Figure 14: Type 38-3AH3 vacuum circuit breaker pole section on page 19. The vacuum interrupter (30.0) is rigidly connected to the upper terminal and pole support (20.0) by its terminal bolt (31.2). The lower part of the vacuum interrupter is stabilized against lateral forces by a centering ring (28.1) on the pole-support (40.0). The external forces due to switching operations and the contact pressure are absorbed by the struts (28.0).

Current-path assembly

Refer to Figure 14: Type 38-3AH3 vacuum circuit breaker pole section on page 19. The current-path assembly consists of the upper terminal and pole support (20.0), the stationary contact (31.0) and the moving contact (36.0), that is connected with the lower terminal (29.0) by terminal clamp (29.2) and a flexible shunt (29.1).

Vacuum interrupter

Refer to Figure 9: Vacuum interrupter cutaway view on page 15. The moving- contact (36.0) motion is aligned and stabilized by guide bushing (35.0). The metal bellows (34.0) follows the travel of contact (36.0) and seals the vacuum interrupter against the surrounding atmosphere.

Switching operation

Refer to Figure 14: Type 38-3AH3 vacuum circuit breaker pole section on page 19. When a closing command is initiated, the closing spring, that was previously charged by hand or by the motor, actuates the moving contact (36.0) through jack shaft (63.0), lever (63.7), insulated coupler (48.0) and lever (48.6).

The motion of the insulated coupler is converted into the vertical movement of the moving contact.

The moving-contact motion is controlled by the guide link (48.9), that pivots on support (40.0) and the eye bolt (36.3).

During closing, the tripping spring and the contact-pressure springs (49.0) are charged and latched by the pawl (64.1). The closing spring is recharged immediately after closing.

In the CLOSED state, the necessary contact pressure is maintained by the contact- pressure spring and the atmospheric pressure. The contact-pressure spring automatically compensates for contact erosion, which is very small.

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Contents Answers for energy Qualified person Table of contents Signal words Hazardous Procedures IntroductionIntroduction Field service operation and warranty issues IntroductionIntroduction Receiving procedure Receiving, handling and storageShipping damage claims Handling procedure Receiving, handling and storageOutdoor storage Storage procedureIndoor storage Space heatingInstallation checks and functional tests Inspections, checks and tests without control powerDe-energizing control power in switchgear Installation checks and functional tests Racking crank engagement procedure Type 38-3AH3 vacuum circuit breaker rackingPhysical inspections Manual-spring charging checkFinal mechanical inspections without control power Split-plug jumper connected to circuit breakerVacuum interrupter/ operator Vacuum interrupter/ operator Vacuum interruptersPhase barriers Primary disconnectsStored-energy operating mechanism Interrupter/operator module ConstructionCircuit-breaker pole Current-path assemblySwitching operation Vacuum interrupterType 38-3AH3 vacuum circuit breaker pole section Stored-energy operating mechanism Operating mechanism Auxiliary switchMode of operation Indirect releases tripping coilsClosing Use of manual-spring operation crankRapid auto-reclosing Trip-free functionalityOpening 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 Secondary shunt release optional Indirect releases dual-trip orUndervoltage optional 54.2Position a locked Capacitor-trip device Shock absorberSecondary disconnect Mechanism-operated cell MOC switch optional Truck-operated cell TOC switchShutter-operating linkage Secondary disconnect Shutters Circuit-breaker frame Trip-free interlockRating interlock Ground disconnectAlignment Racking mechanismVehicle function and operational interlocks Interlocks Circuit breaker racking-interlocksRacking interlocks Closed circuit breaker interlock Automatic closing-spring energy release Trip-free interlock position mechanical interlock Maintenance Introduction and maintenance intervalsMaintenance Recommended hand toolsRecommended maintenance and lubrication Inspection items and testsRemoval from switchgear Checks of the primary power pathCleanliness check Inspection of primary disconnects Maintenance and lubricationCircuit Number Checks of the stored-energy operator mechanismTypical for all three-phases Fastener check Manual-spring charging and contact- erosion checksElectrical-control checks Wiring and terminals checkAutomatic spring-charging check control power required Secondary-disconnect checkTypical vacuum interrupter contact curve Spring-charging motor checks Vacuum-interrupter mechanical checkVacuum-integrity check using dielectric test High-potential testsHigh-potential test voltages Field-test voltage Voltage Frequency withstandRating a Inspection and cleaning of circuit- breaker insulationContinuous Contact Functional testsCircuit-breaker overhaul Replacement at overhaulOverhaul Circuit breaker Number TypeVacuum interrupter replacement OverhaulSetting Vacuum interrupter replacement illustration Overhaul Checking the contact stroke Open the circuit breaker Hydraulic shock absorberMaintenance and troubleshooting Sub-assembly Inspect forMaintenance and troubleshooting Problem Symptoms Possible causes and remediesClosed Appendix Appendix Values Voltage Voltage range factor K3 Insulation Withstand Permissible tripping delay YMaximum design voltage Voltage levels Lightning-impulse BILRated Continuous4 Rated Maximum design voltageLevels Voltage levels Lightning-impulse BIL 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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