SIEMENS 3AH3 vacuum circuit breaker

SIEMENS 3AH3 vacuum circuit breaker

Product Overview and Core Features

Basic positioning: Siemens 3AH3 vacuum circuit breaker belongs to medium voltage equipment, with document version 2018 (HG 11.03), replacing the old version 2010. The product production and sales follow ISO 9001, ISO 14001, BS OHSAS 18001 certification management system.

Core advantages:

Maintenance free design: Under normal conditions (compliant with IEC 62271-1), there is no need for re lubrication or adjustment throughout the entire service life, and the characteristics are not affected by switching frequency or idle time. It supports up to 10000 operating cycles.

Wide voltage coverage: Suitable for the conventional medium voltage range of 7.2kV-40.5kV, meeting the needs of industrial and generator scenarios.

High load capacity: The maximum rated normal current of conventional models is 6300A, and the maximum short-circuit breaking current is 72kA; under the "phase separation" design scheme, the maximum rated normal current is 12000A, and the maximum short-circuit breaking current is 90kA.

Product Classification and Applicable Standards

1. Product classification and scenarios

Product type follows standard core applicable scenarios and key enhanced features

Conventional high-voltage circuit breakers IEC 62271-100 are used in industrial scenarios (such as oil refineries) to control small inductive/capacitive load currents to high-voltage short-circuit currents-

Generator circuit breaker (3AH3 6/7/8 series) IEC 62271-100+IEC/IEEE 62271-37-013 Generator operation, switching between generator power supply failure and system power supply failure 1. Coping with generator power supply failure: high DC component, no current zero point; 2. Coping with system power supply failures: higher TRV rise rate; 3. Higher testing voltage level

Split phase design circuit breaker IEC 62271-100+IEC/IEEE 62271-37-013 for large generator switchgear, single-phase isolating switch (independent enclosure) 1. Optimize parallel operation; 2. The maximum short-circuit breaking current is 90kA; 3. The maximum rated normal current is 12000A

2. General standard compliance

Basic standards: IEC 62271-100 (for circuit breakers), IEC 62271-1 (for medium voltage equipment) VDE 0671

Endurance level: All 3AH3 vacuum circuit breakers meet the E2, M2, C2, and S1 levels (IEC 62271-100)

Structure and Working Principle

1. Core structure (including component functions)

Core functions of structural components

Pole component (1) vacuum arc extinguishing chamber (6), upper/lower arc extinguishing chamber bracket (5/7), post insulator (3) 1. Vacuum arc extinguishing chamber: based on more than 40 years of mature vacuum switch technology, arc extinguishing is achieved; 2. Air insulation design, easy to clean insulation components; 3. Bear the external force and contact pressure of switch operation

Operating mechanism box (2) includes energy storage mechanism, release device, auxiliary switch, indicator, and actuator 1. It accommodates all operating mechanisms; 2. The configuration of secondary devices can be adjusted according to application scenarios to meet diverse needs

Transmission component operating rod (4), lever transmission switch action, connecting operating mechanism and pole assembly

2. Key operational mechanisms

Energy storage mechanism: The closing spring is an energy storage component that can store energy electrically or manually, and is locked after the energy storage is completed; When closing, unlock through the local "ON" button (mechanical) or remote control (electric). During the closing process, charge the opening/contact pressure spring, and automatically re store energy after discharge. It supports the OPEN-CLOSE-OPEN operation sequence.

Free release mechanism: in accordance with IEC 62271-100, if a closing command is issued and an opening command is received, the moving contact returns to the opening position and maintains it, avoiding continuous closing opening "pumping".

Closing method:

Standard configuration: Remote electric closing, local mechanical unlocking closing spring (manual mechanical closing)

Optional configuration: Manual electric closing (electrically controlled closing circuit through button, compatible with switch equipment interlocking)

3. Types and functions of release devices

Release type, power supply method, core function

Closing the soleoid DC/AC unlocks the stored energy closing spring to achieve electrical closing

External power supply (DC/AC) for shunt release, connected to voltage transformer in special circumstances. 1. Automatic disconnection through protective relay; 2. Electrical manual disconnection

When the CT operated release has no external auxiliary power supply (such as no battery), it is triggered by a protective relay (such as overcurrent time protection). When the tripping current exceeds 90% of the rated normal current, the energy storage mechanism is unlocked and the circuit is opened

When the undervoltage release circuit breaker is closed, it is permanently connected to the secondary/auxiliary voltage. When the voltage is lower than the preset value, it is unlocked and opened through the energy storage mechanism; 2. Can be connected to a voltage transformer, which automatically opens when the voltage is too low; 3. Can be paired with energy storage components to achieve delayed disconnection