Vacuum circuit breaker is a kind of electrical switch, with overload, short circuit and undervoltage protection function, have the ability to protect the line and power supply, its small size, light weight, suitable for breaking capacitive load current. At present, the survival of the vacuum circuit breaker manufacturers are more, the model is also more, so in the selection of the time always feel dazzled. Here's an introduction to vacuum circuit breakers

About the empty circuit breaker number

At present the model mainly has: ZN12-10 type, ZN28A-10 type, ZN65A-12 type, ZN12A-12 type, VS1 type, ZN30 type, etc. At present, according to the national technical standards, the circuit breaker models in China are generally composed of word symbols and numbers in the following way: the meanings of the representatives are.

① product letter code, with the following letters: S - less oil circuit breakers; D - multi-oil circuit breakers; K - air circuit breakers; L - sulfur hexafluoride circuit breakers; Z - empty circuit breakers; Q - gas-producing circuit breakers; C - magnetic blowing circuit breakers.

② Device location code:; N - indoor, W - outdoor.

③ design series sequence number:; to the number 1, 2, ..... Show.

④Rated voltage, KV.

⑤- Supplementary operating characteristics mark, G- Improved, F- Phase separation operation. ⑥-rated current, A. ⑦-rated breaking current, KA.

Vacuum circuit breaker characteristics.

①Small contact opening distance, 10KV vacuum circuit breaker contact opening distance is only about 10mm, the operating work of the operating mechanism is small, the mechanical part of the stroke is small, its mechanical life is long.

②The arc burning time is short, and has nothing to do with the size of the switch current, generally only half a week wave.

③After the arc is extinguished, the contact gap medium recovers quickly, and the fault performance of the opening area is better.

④ Because of the small amount of wear and tear when opening and closing the current, so the electroforming life of the contact is long, full capacity opening and closing up to 30-50 times, rated current opening and closing up to 5 More than 000 times, the noise is small and suitable for frequent operation.

⑤Small volume and light weight.

⑥It is suitable for breaking capacitive load current.

Select vacuum circuit breaker method

1、Choose the type of circuit breaker according to the cabinet type, for indoor fixed type 10KV switchgear, most of them choose ZN28 type vacuum switch, with spring operation mechanism, can be AC or DC electric operation, also can be manually operated for indoor move away type 10KV switchgear (such as KYN type), can choose VS1 type vacuum switch, with spring integrated operation mechanism, can bite, DC electric operation, also can be manually operated.

2、Select the rated current of the circuit breaker. General distribution circuit breakers are 630A, 1000A, 1250A, 1600A four, you should calculate the load current flowing through the circuit breaker according to the load, and then leave Yu, selected its rated current;, 2000KVA transformer, its rated current | = 2000 / (1.732 * 10) = 115. 5A, you can initially choose 630A circuit breaker, but should also Calibration

3, calibrate the selected circuit breaker breaking current. Calculate the short-circuit current value of the installation site of the circuit breaker, and the initial selected circuit breaker breaking current value for comparison, the circuit breaker breaking current value after leaving the margin, should be greater than the installation site of the maximum short-circuit current value, so as to ensure that the circuit breaker in the event of a short circuit, can reliably act to remove the fault itself is not damaged, a general 10KV vacuum circuit breaker rated short-circuit breaking current value of more than 20KA. 25KA, 31.5KA, 40KA, corresponding to the above 630A, 1000A, 1250A, 1600A four rated currents, if the 2000KVA transformer installation site is close to the substation exit, the maximum short-circuit current value of 26KA, the use of 630A switch its rated short-circuit breaking current of 20KA will not meet the requirements of the point of use The rated current should be 1250A, rated short-circuit breaking current of 31.5KA circuit breaker.

4, other cases of calibration. Such as the distance between phases, installation size, interlocking situation, whether there is a blocking, whether with overcurrent coil, whether with loss of voltage, etc.