Siemens 38-3AH3 38 kV Fastener check, Manual-spring charging and contact- erosion checks

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Maintenance

Figure 40: Contact-erosion check mark dot circled in orange (shown with circuit breaker OPEN)

Primary-disconnect contacts (multi- fingered clusters) and secondary- disconnect contacts (strips and fingers) are to be wiped clean, and a film of Siemens contact lubricant (15-172-791-233) applied. Avoid getting contact lubricant on any insulating materials.

Fastener check

Inspect all fasteners for tightness. Both locknuts and retaining rings are used. Replace any fasteners that appear to have been frequently removed and replaced.

Manual-spring charging and contact- erosion checks

Perform the manual-spring charging check contained on page 12 in the section "Installation check and initial functional tests." The key steps of this procedure are repeated here.

1.Insert the hand-charging crank into the manual-charge socket at the front of the operator control-panel. Turn the crank clockwise (about 48 revolutions) to charge the closing spring. Continue cranking until the CHARGED flag appears in the window of the spring- indicator.

2.Press the close (black) pushbutton. The contact-position indicator on the operator-control panel should indicate the circuit-breaker contacts are

CLOSED.

3.Perform the contact-erosion check. Contact erosion occurs when high-fault currents are interrupted or when the vacuum interrupter is nearing the limit of its contact life. Determination of acceptable contact condition is checked by the visibility of the white- erosion mark (refer to Figure 40: Contact-erosion check mark dot circled in orange (shown with circuit breaker OPEN)). The white-erosion mark is located in the keyway (or slot) on the movable stem of the vacuum interrupter, near the plastic-guide bushing.

The contact-erosion check procedure is:

A.Be sure the circuit-breaker primary contacts are CLOSED.

B.Observe the white-erosion mark of each pole (refer to Figure 36: Trip- control pushbutton (lower button) on page 43). When this mark is visible, contact wear is within acceptable limits.

4.Press the red trip pushbutton after completing the contact-erosion check. Visually verify the DISCHARGED condition of the closing springs and the circuit-breaker contacts are OPEN.

5.Press the black close pushbutton. Nothing should happen. The manual- spring check should demonstrate smooth operation of the operating mechanism.

High-speed moving parts.

Can result in serious injury.

Tripping spring is charged. If trip latch is moved, the stored- energy springs will discharge rapidly.

Stay clear of circuit breaker components subject to sudden, high- speed movement.

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Contents Answers for energy Qualified person Table of contents Introduction Signal words Hazardous ProceduresIntroduction Field service operation and warranty issues IntroductionReceiving, handling and storage Introduction Receiving procedureShipping damage claims Handling procedure Receiving, handling and storageOutdoor storage Storage procedureIndoor storage Space heatingInspections, checks and tests without control power Installation checks and functional testsDe-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 interruptersPrimary disconnects Phase barriersStored-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 Shock absorber Capacitor-trip deviceSecondary 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 testsChecks of the primary power path Removal from switchgearCleanliness 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 checkHigh-potential tests Vacuum-integrity check using dielectric testHigh-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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