The Siemens 3AH3 series vacuum circuit breaker is a medium voltage equipment with a rated voltage of 7.2kV-40.5kV. Its core advantage is maintenance free throughout its entire life cycle (supporting 10000 operating cycles), with a rated current of up to 12000A and a maximum short-circuit breaking current of 90kA. It is divided into universal type (compliant with IEC 62271-100) and generator specific type (additionally compliant with IEC/IEEE 62271-37-013), using vacuum arc extinguishing technology and energy storage operating mechanism, supporting electrical/manual operation and electrical/mechanical interlocking, suitable for industrial, generator and other scenarios, providing flexible secondary equipment configuration and rich accessories to meet the switching and protection needs of diversified medium voltage power supply systems.

Product basic information

Product positioning and certification:

Equipment type: Medium voltage vacuum circuit breaker, suitable for 7.2kV-40.5kV medium voltage power supply system

Core features: Maintenance free throughout the entire lifecycle, no need for re lubrication or adjustment, supporting 10000 operating cycles

Management System Certification: Compliant with ISO 9001 (Quality), ISO 14001 (Environment), OHSAS 18001 (Occupational Health and Safety) standards

Product standards: The universal type complies with IEC 62271-100, and the generator specific type additionally complies with IEC/IEEE 62271-37-013 (for high requirements of generator switches)

Product Categories:

Classification Applicable Scenarios Key Standards Special Requirements

General purpose (high current circuit breaker) industrial distribution, medium voltage line switch IEC 62271-100 supports conventional load current and short-circuit breaking

Generator specific generator connection and protection IEC 62271-100+IEC/IEEE 62271-37-013 withstand high DC components, high TRV rise rate, and higher test voltage

The phase separation design of the large generator phase separation switch equipment corresponds to one circuit breaker for the above dual standard single-phase, supporting parallel operation, with a maximum short-circuit breaking current of 90kA

Core structure and working principle

Structural composition:

Main structure: composed of pole components and operating mechanism box, fixed by pillar insulators, and the operating rod and lever transmit switch actions

Pole component: includes a vacuum arc extinguishing chamber (air insulated, freely accessible, easy to clean), with upper and lower arc extinguishing chamber brackets fixed, and the lower part can move axially

Operating mechanism box: integrated energy storage operating mechanism, release device, auxiliary switch, indicator, etc., secondary equipment configuration can be selected as needed

Core mechanism:

Arc extinguishing technology: Vacuum arc extinguishing, based on more than 40 years of mature technology, stable arc extinguishing effect

Operating mechanism: Energy storage type, closing spring can store energy electrically or manually, lock after energy storage, unlock and close through electrical remote control or local button

Free release mechanism: After the closing action is initiated, if a disconnection command is received, the moving contact will immediately return to the disconnection position and maintain it to prevent the “pump effect” (continuous opening and closing)

Action process: When closing, the closing spring releases energy and stores energy for the opening spring/contact pressure spring, completing the “opening closing opening” operation sequence storage

Key performance parameters

Electrical parameters:

Key Explanation of Parameter Category Range

Rated voltage (Ur) 7.2kV, 12kV, 17.5kV, 24kV, 36kV, 40.5kV covering mainstream medium voltage levels

Rated current (Ir) 1250A-12000A, conventional 1250A-6300A, phase separated design can reach 12000A

Short circuit breaking current (Isc) 31.5kA-90kA, universal type up to 63kA, phase separated generator type up to 90kA

Rated lightning impulse withstand voltage (Up) 60kV-195kV needs to be calibrated according to the coefficient Ka as the altitude increases (altitude>1000m)

Rated short-time power frequency withstand voltage (Ud) 20kV-95kV same altitude calibration requirements

Action time: Closing<75ms, opening<60ms, arcing<15ms. Shorter action time can be customized as needed

Environment and adaptation parameters:

Environmental climate level: Climate category 3K4 (low temperature -5 ℃), Biological category 3B1, Chemical category 3C2, Mechanical category 3M2, Mechanical active substance category 3S2

Altitude adaptation: The reference altitude is 1000m, and if exceeded, the insulation level needs to be increased (correction formula: U ≥ U ₀ × Ka)

Current carrying capacity: operate at rated current in an environment of 40 ℃, and can carry higher current below 40 ℃

Configuration and selection

Basic configuration options:

Key Explanation of Optional Solutions for Configuration Categories

Electric operating mechanism, manual operating mechanism (including handle), and electric motor mechanism require specified control voltage

Closing method: Solenoid+manual mechanical closing, manual electrical closing. Manual electrical closing supports interlocking of switch equipment to prevent accidental closing

When there is no external auxiliary power supply, a maximum of 3 release combinations (shunt/undervoltage/current transformer operation) can be selected for current transformer operation release

The number of contacts for auxiliary switches 6NO+6NC and 12NO+12NC can be selected as needed, and they support gold plating treatment (in special environments)

Low voltage interface 24 pole terminal block, 24 pole plug, 64 pole plug DC ≥ 60V recommended plug

Additional configuration (optional):

Overvoltage suppression: Varistor protection circuit (limiting overvoltage of inductive load switch)

Protection function: Condensed water protection heating device (110V/230V AC, 50W), silicon free design, -25 ℃ low temperature operation adaptation

Connection accessories: wire harnesses of different lengths (500mm-3500mm), 30 pole terminal blocks, dual 24 pole terminal blocks/plugs

Special functions: Spring release device (releases energy storage when the plug is disconnected), priority tripping (prevents closing during opening operation)

Ordering coding rules:

Order number structure: 16 bit code, the first 8 bits define the main circuit parameters (voltage, current, breaking current, pole spacing, etc.), and the last 8 bits define the secondary equipment (operating mechanism, release, voltage, etc.)

Special version: suffix “- Z” plus 3-digit encoding, supports customized requirements (such as special insulation level, environmental adaptation)

Application scenarios and accessories

Typical applications:

Industrial scenarios: High voltage load current (up to 6300A) and high short-circuit current (up to 72kA) scenarios in refineries, large industrial plants, etc

Power generation scenario: Generator outlet switch, phase separated design suitable for large generators (rated current 4000A-12500A)

Transformation scenario: Replace compressed air generator circuit breakers and adapt to retrofit projects

Accessories and spare parts:

Operating accessories: manual energy storage handle (short/standard/long design), battery screwdriver bit, crimping pliers, disassembly tool

Electrical spare parts: vacuum arc extinguishing chamber (with adapter), release, closing soleoid, auxiliary switch, plug connector (24 pole/64 pole)

Consumables: lubricating oil (Kl ü ber Isoflex Topas L32N), special oil (Shell Tellus 32), wiring harness (compatible with auxiliary switches and plugs)