What are the specific technical parameters of the vacuum circuit breaker

The name of the parameter. Unit.

Model. zn28-12/1250-20

zn27-12/

zn27a-12/3150-40

Voltage parameters. Vacuum circuit breaker model specifications.

Rated voltage. kv

Maximum voltage. Insulation level. Power frequency withstand voltage.

Between the poles, the poles on the ground.

Between the fractures. Impact pressure. Between the poles, the poles on the ground.

Between the fractures. Current Parameter Rated current. a

Rated short-circuit breaking. ka

Rated peak withstand current. ka

4s short-time withstand current. ka

Rated short-time closing current (peak) ka

Rated breaking current for a single capacitor bank. a

Rated back-to-back capacitor bank interrupting current. a

Life span. Rated number of short-circuit interrupting currents. Times.

Mechanical life. Times.

Other. Rated sequence of operations.

Split and combine-180s-combine.

min-180s-combine-180-combine.

The number of full breaks.

Not more than 60 with operating mechanism.

CD or CT institutions.

Rated voltage, rated current, 1min power frequency withstand voltage, rated lightning impulse withstand voltage, rated short-circuit breaking current, rated short-circuit breaking current times, mechanical life and other parameters.

IR: setting value of overload long delay trip current;

TR: overload long delay trip time;

ii: short-circuit instantaneous trip current setting value;

ISD: short-circuit short-delay tripping current setting value;

TSD: short-circuit, short-delay, and detoxification time.

Vacuum circuit breaker "main structure:

The vacuum circuit breaker mainly consists of three parts: vacuum interrupter, electromagnetic or spring operating mechanism, bracket and other components.

1. Vacuum interrupter:

According to the different types of switches, there are outer shielding cover type ceramic vacuum interrupter, CTS Hengjian sealed cup-shaped longitudinal magnetic field miniaturized vacuum interrupter, and inner sealed glass bubble interrupter, and its basic structure is as follows:

1. Airtight insulation system (shell).

The airtight insulation system consisting of an airtight insulating cylinder made of ceramic, glass or glass-ceramic, a moving end cover, a fixed end cover, and a stainless steel bellows is a vacuum-tight container. In order to ensure air tightness, in addition to strict operation procedures in the sealed type, it is also required that the material itself has air permeability and small internal air release.

2. Conductive system.

It is composed of a fixed conductive rod, a fixed slag annihilation arc surface, a fixed contact, a moving contact, a dynamic running arc surface, and a dynamic conductive rod. There are roughly three types of contact structures: cylindrical contacts, transverse magnetic field contacts with spiral groove arcing surfaces, and longitudinal magnetic field contacts.

At present, the longitudinal magnetic field technology is adopted, and this kind of arc extinguishing chamber has a strong and stable arc breaking ability.

3. Shielding system.

The shield is an indispensable element in the vacuum interrupter, and there are various types of shields such as the main shield around the contacts, the bellows shield, and the shield for equalizing pressure.

The function of the main shield is: a to prevent the arc products from splashing into the inner wall of the insulated shell during the arcing process, thereby reducing the dielectric strength of the shell. bImprove the uniformity of the electric field distribution inside the arc extinguisher, which is conducive to reducing the local field strength and promoting the miniaturization of the vacuum interrupter.

c. Condensate arc products, absorb part of the arc energy, and help to restore the strength of the medium behind the arc.

Second, the operating mechanism:

According to the different types of circuit breakers, the operating mechanisms used are different. Commonly used operating mechanisms include spring operating mechanism, CD10 electromagnetic operating mechanism, CD17 electromagnetic operating mechanism, CT19 spring energy storage operating mechanism, and CT8 spring energy storage operating mechanism.

3. Other components:

Pedes, insulating supports, insulators, etc.

Answers]: a, c, d

The high-voltage vacuum grinding circuit breaker is the use of "vacuum" as the insulation and arc extinguishing medium, and the vacuum circuit breaker has three forms: floor-mounted blind celery, suspension type and handcart type. It dominates the voltage class of the 35 kV distribution system and below.