Siemens 38-3AH3 38 kV instruction manual Checking the contact stroke Open the circuit breaker

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Overhaul

2.9Tighten upper fastening bolt (31.2) on the upper pole-support (20.0) holding the vacuum interrupter firmly by its upper insulator and operate levers (48.6) by hand to see whether the movable contact moves freely. If any binding or lack of freedom is noted, loosen bolt (31.2) and adjust the vacuum interrupter in pole support by turning the vacuum interrupter and moving it slightly. Torque M16 bolt to 91-101 ft-lb (123- 137 Nm).

2.10The centering ring (28.1) has been loose and floating during installation of the vacuum interrupter. Check that the movable contact is free to move vertically without binding, and then tighten the hardware that secures the centering ring. Re-check that the movable contact is free to move vertically without binding.

2.11Attach insulating coupler (48.0) and lever (48.6) together, using pin

(48.5). Apply retaining clips. Correct pin has ends that have been generously chamfered.

2.12Open and close circuit breaker several times and then check to see that all bolted joints and devices are tight.

3.0Checking the contact stroke

3.1Open the circuit breaker.

3.2Free insulating coupler (48.0) by removing pin (48.5). The vacuum interrupter contacts must now close automatically as a consequence of atmospheric pressure.

3.3Observe the terminal clamp (29.2) through the openings on each side of the lower pole support (40.0).

Using vernier calipers measure the distance from the bottom surface of the terminal clamp to the bottom edge of the cutout opening. Measure carefully and record your result.

3.4Connect the insulating coupler (48.0) using pin (48.5) and the retaining clips provided.

3.5Repeat the measurement described in step 3.3 again with care to maximize accuracy. Record your result.

3.6Determine difference between the measurements made under steps 3.3 and 3.5. Your result should be 18 mm to 22 mm (0.709" to 0.866 ").

3.7If you fail to achieve the listed results, carefully repeat the entire procedure making certain of your measurements.

3.8Loosen locking nut on eye bolt on insulated coupler (48.0), and retain position of the eye. Make adjustments in one-half turn increments. After adjustment is completed, tighten eye- bolt locking nut to 26-34 ft-lb

(35 to 45 Nm).

4.0After eye bolt is tightened to proper torque, repeat all measurement procedures, making certain they are in agreement with values indicated in step 3.6.

5.0Complete all other maintenance procedures. Completely reassembled circuit breaker should pass high- potential test before it is ready for service.

Hydraulic shock absorber

The type 38-3AH3 mechanism is equipped with hydraulic shock-absorber and a stop bar that functions when the circuit breaker opens (refer to Figure 15: Stored-energy operating mechanism on page 20). The shock absorber (61.8) should require no adjustment. However, at maintenance checks, the shock absorber should be examined for evidence of leaking. If evidence of fluid leakage is found, the shock absorber must be replaced to prevent damage to the vacuum-interrupter bellows.

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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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