Air switch generally known for low voltage circuit breaker, not limited to the small DZ47 air switch. It is currently the most widely used in industrial automatic production of electrical products, has many types, models etc.. In this paper, the people of Shanghai electric appliance switch factory technical personnel and we will talk about a general Communist production should be how to choose a suitable air products.

A common categories: air switch

( 1) device type circuit breaker device type circuit breaker has an insulating plastic shell, inner contact system, interrupter and tripping device, can be manual or electric (on large capacity circuit breaker closing character ). High breaking capacity and dynamic stability, better selectivity protection function, widely used for power distribution line. The current commonly used with DZ15, DZ20, DZX10 and C45N ( has been upgraded to C65N ) and other products. Where C45N ( C65N ) circuit breaker has the advantages of small volume, high breaking capacity, limiting performance, convenient operation, complete model specifications, can be conveniently in unipolar structure based on combination of diode, triode, tetrode breaker advantages, widely used in 60A and the following civil lighting trunk line and branch and branch ( for residential users input switch and shopping mall lighting branch switch ).

( 2) a frame type low voltage circuit breaker circuit breaker general capacity is larger, has a high short circuit breaking capacity and higher dynamic stability. Apply to the exchange of 50Hz, rated current 380V distribution network as the main protection of power distribution lines. Frame type circuit breaker is mainly composed of contact system, operating mechanism, the overcurrent tripping device, shunt tripping device and undervoltage tripping device, accessories and frame components, all components are installed on the frame structure after the insulation base. At present our country commonly used with DW15, ME, AE, AH series of frame type low voltage circuit breaker. The DWl5 series circuit breaker is China's own development and production of the series, with 1000, 1500, 2500 and 4000A and several other models. ME, AE, AH series of circuit breaker is the use of imported technology and production. Their specifications are more complete ( ME switch current ratings from 630A to 5000A in all 13 grade ), rated breaking capacity better than DWl5, commonly used in the low voltage distribution line main protection.

( 3) intelligent circuit breaker is the current domestic production of intelligent circuit breaker has a frame and a plastic casing type two. Frame type intelligent circuit breaker is mainly used in intelligent power distribution system of main circuit breaker, plastic shell type intelligent circuit breaker is mainly used in the power distribution network in the distribution of power and the power lines and equipment control and protection, it also can be used in three-phase squirrel cage induction motor control. Intelligent circuit breaker is characterized by the use of a microprocessor or microcontroller as the core of the intelligent controller ( intelligent ), it not only has the common circuit breaker protection function, but also has the real time display circuit in various electrical parameters ( current, voltage, power, power factor, etc. ) on the circuit, on-line monitoring self regulation, measurement, test, self diagnosis, communication and other functions, can be all kinds of protection action parameter display, set and modify, protection circuit when the fault parameters can be stored in nonvolatile memory so that the query, domestic DW45, DW40, DW914 ( AH ), DWl8 ( AE-S, DW48 ), DWl9 ( 3WE ), DWl7 ( ME ) and other intelligent frame circuit breaker and intelligent moulded case circuit breaker, are equipped with ST series intelligent controller and related accessories, ST series intelligent controller is the National Machinery Ministry of " eight five " to " Nine Five " during the key projects. Product performance indicators have reached the international advanced level in the 90's. It adopts a modular package, can be directly installed on the circuit breaker body, without having to repeat the two wiring, and a variety of programmes in any combination.

Two: air switch selection principle

1) according to the requirements of the protection of line circuit breaker determines types and forms of protection - - determine the selection of frame type, device type or current-limiting type.

2) circuit breakers rated voltage of UN should be equal to or greater than the rated voltage of the protected circuit.

3) the circuit breaker rated voltage should be equal to the rated voltage of the protected circuit.

4) the rated current of the breaker and overcurrent tripping device should be greater than or equal to the rated current of the protected circuit is the current calculation.

5) circuit breaker breaking the limits of capacity should be greater than the line the maximum short-circuit current effective value.

6) the distribution line in the upper, the lower circuit breaker protection characteristics should coordinate, subordinate protection characteristics should be located at the superior protection properties below and do not intersect.

7) the long time delay trip breaker current shall be less than the wires allowing continuous current.

I hope this for us to know how to choose the air switch and can help!