What is an Air Switch?

What is an Air Switch?

Air circuit breaker definition

Air circuit breaker is a kind of high voltage circuit breaker which uses air as arc extinguishing medium. Compared with other types of high-voltage circuit breakers such as SF6 circuit breakers and vacuum circuit breakers, air circuit breakers are usually suitable for lower voltage levels of power systems.

Constituent structure

• Auxiliary contact

• Alarm contact

• Shunt release

• Undervoltage release

• Electric operating mechanism

• Turning handle

• Extension handle

• Handle locking device

Working principle

The working principle of the air circuit breaker is based on the arc extinguishing characteristics of the air. When the circuit breaker needs to disconnect the circuit, the moving contacts and the static contacts are separated in the air, and the arc between the contacts is generated in the air. Because the air has a certain insulating strength, the arc is gradually extinguished in the process of separating the contacts, thus cutting off the current. When the circuit needs to be closed again, the contacts re-contact and the circuit recovers.

Working condition

Ambient air temperature: ambient air temperature upper limit +40℃; Ambient air temperature limit -5℃; The average ambient air temperature for 24h does not exceed +35℃.

Elevation: The elevation of the installation site does not exceed 2000m.

Atmospheric conditions: the relative humidity of the atmosphere does not exceed 50% when the ambient air temperature is +40℃; It can have higher relative humidity at lower bottom temperature. The monthly average maximum relative humidity of the wettest month is 90%, while the monthly average minimum temperature of the month is +25 ° C, taking into account the condensation that occurs on the surface of the product due to temperature changes.

Pollution level: Pollution level is 3.

Advantage

• Lower cost

• Simple structure

• Environmental protection

• Scope of application

• Arc extinguishing capability

Application scenario

Power distribution system: used to control and protect medium and low voltage power distribution lines.

Industrial facilities: Used to protect small and medium-sized motors and power equipment.

Building power distribution: Used for power distribution systems within buildings.

Small power stations: For the transmission and distribution of electricity in small power stations.

Sum up

Air circuit breaker is a commonly used electrical protection equipment, with simple structure, easy installation, easy operation and relatively low price characteristics, widely used in household, commercial and industrial electricity and other fields. When selecting and using air circuit breakers, appropriate products should be selected according to actual needs, and attention should be paid to correct installation and maintenance to ensure the safe and stable operation of the power system.