Outdoor Vacuum Circuit Breaker--ZW8-12 Outdoor Vacuum Circuit Breaker

When the circuit breaker receives a tripping signal, the operating mechanism acts, causing the moving contact to move from the closed position to the open position. At the moment when the moving and fixed contacts separate, an arc is generated due to the increase in the contact resistance between the contacts.

The vacuum environment in the vacuum interrupter enables the arc to be quickly extinguished when the current crosses zero, thus achieving the disconnection of the circuit.

During the closing process, the operating mechanism makes the moving contact move towards the fixed contact until they come into contact and complete the closing operation, thereby connecting the circuit.

Product Detail

working principle

The vacuum environment in the vacuum interrupter enables the arc to be quickly extinguished when the current crosses zero, thus achieving the disconnection of the circuit.

Product Features

Strong arc extinguishing ability: It adopts a vacuum interrupter, with vacuum as the arc extinguishing and insulating medium. It can quickly extinguish the arc, and the breaking performance is stable.
High reliability: The permanent magnet operating mechanism is provided with a holding force by a permanent magnet. With fewer mechanical parts and a short transmission chain, it improves the reliability and mechanical life of the switch.
Good insulation performance: It adopts a post-type fully enclosed solid insulation structure or the technology of completely encapsulating the main body. It has good sealing performance and can adapt to harsh environments.
Easy operation: It can be operated manually or electrically, and can also be remotely controlled. It can also cooperate with a controller to achieve the "four remote" functions (remote measurement, remote control, remote signaling, and remote regulation).
Small in size and light in weight: With a compact structure, it is convenient for installation and transportation.
Low maintenance cost: It has a long mechanical life. There is no need for maintenance or adjustment within 30,000 operations, featuring maintenance-free characteristics.

Product Parameters

Electrical Parameters

Rated voltage: 12kV
Rated frequency: 50Hz
Rated current: Usually 630A, and some models may also support 400A, 200A, etc.
Rated short - circuit breaking current: Common values are 20kA, 16kA, 12.5kA, etc.
Rated peak withstand current: Corresponding to the rated short - circuit breaking current, it is generally 50kA (for example, when the rated short - circuit breaking current is 20kA)5.
Rated short - time withstand current: The same as the rated short - circuit breaking current, such as 20kA/4s, 16kA/4s, 12.5kA/4s, etc.
Rated short - circuit making current (peak value): The same as the rated peak withstand current, like 50kA5.
Rated operating sequence: Open - 0.3s - Close and open - 180s - Close and open5.
Rated insulation level5:
- 1 - minute power - frequency withstand voltage (dry): 42kV between phases and to the ground.
- Lightning impulse withstand voltage (peak value): 75kV between phases and to the ground.

Mechanical Parameters

Mechanical life: Usually 10,000 times5.
Number of operations at the rated short - circuit breaking current: Generally 30 times5.
Contact opening distance: 11 ± 1mm5.
Over - travel: 3mm5.
Three - phase contact opening and closing synchronism: ≤ 2ms5.
Contact closing bounce time: ≤ 2ms5.
Average opening speed: 1.0 ± 0.2m/s5.
Average closing speed: 0.7 ± 0.15m/s5.
Opening time: 0.015 - 0.05s under the highest operating voltage and 0.03 - 0.06s under the lowest operating voltage.
Closing time: 0.025 - 0.05s.

Other Parameters

Resistance of each phase main circuit: ≤ 120μΩ5.
Allowable wear thickness of moving and stationary contacts: 3mm5.
Rated operating voltage (closing/opening coil): Usually DC 220V, AC 220V, and some models also support 110V25.