TD-12/1250A High-voltage Vacuum Interrupter, Vacuum Tube for 10KV Circuit Breakers, Applicable to ZN12, ZN23 and VS1 series

The TD-12/1250A is a core model of indoor high-voltage vacuum interrupter with a rated voltage of 12kV and a rated current of 1250A. The suffix numbers (such as -20/-25/-31.5) represent the rated short-circuit breaking current (kA), and the complete parameters need to be confirmed with the specific suffix.

Core specification parameters (typical values, take -20A/-25A/-31.5A as examples)

Rated voltage: 12 kV

Rated current: 1250 A

Rated short-circuit breaking current: 20 kA / 25 kA / 31.5 kA (depending on the suffix)

Rated frequency: 50 Hz

Power frequency withstand voltage (1min): ≥42 kV

Lightning impulse withstand voltage (peak value): ≥75 kV

Mechanical life: 20,000~30,000 times

Short-circuit breaking times: 30~50 times (full capacity)

Contact separation distance: 9±1 mm

Loop resistance: ≤20 μΩ (typical value)

Internal air pressure: ≤1.0×103 Pa

Enclosure material: Ceramic or glass (middle-sealed structure)

Contact material: Copper-chromium alloy (CuCr), mostly with longitudinal magnetic field structure

Key structure and installation notes

Structure type: Middle sealed type, including static/dynamic end covers, main screen covers, CuCr contacts, and stainless steel bellows.

Torque limit: The moving conductive rod can withstand a torsional moment of ≤40 N·m, and anti-rotation measures must be taken during assembly, and the bellows are strictly prohibited from being damaged.

Matching requirements: The contact separation distance, overtravel and opening and closing speed parameters of the circuit breaker operating mechanism must be matched, otherwise the service life and breaking performance will be affected.

Storage period: It can usually be stored for 5~10 years in unopened state, and it needs to be stored in a moisture-proof, shock-proof and non-corrosive gas environment.

Application scenarios and selection tips

This interrupter is specially used for 12kV indoor vacuum circuit breakers (such as VS1, ZN63, ZN28 and other series), and is suitable for breaking load current and short-circuit faults in power distribution systems. When purchasing, be sure to check the short-circuit breaking current rating (that is, the number at the end of the model), and different ratings cannot be mixed; the specific electrical and mechanical data shall be subject to the manufacturer's datasheet, as the parameters of different manufacturers are slightly different.