What are the specific aspects of choosing the correct high-voltage circuit breaker?

Circuit breaker selection principles:

First select according to normal conditions, and then verify according to short circuit conditions. In addition, the rated breaking current of the circuit breaker must be greater than the maximum short-circuit current that may pass through the circuit breaker to ensure that the circuit breaker can reliably extinguish the arc. The specific content of the selection is as follows.

(1).Select according to normal working conditions:

    1). The rated voltage of the high-voltage circuit breaker should be consistent with the grid voltage of the installation location.

    2). The rated current of the high-voltage circuit breaker should be greater than or equal to the long-term maximum operating current in the circuit.

    3). The type of high-voltage circuit breaker should be selected according to the installation environmental conditions. If it is installed outdoors, an outdoor circuit breaker should be selected; if it is installed indoors, an indoor circuit breaker should be selected.

(2). Verify according to short circuit conditions:

    1). Circuit breakers selected according to normal working conditions must also be calibrated according to short circuit conditions. That is to say, it can normally operate safely and reliably. When a short-circuit fault occurs in the circuit, the circuit breaker can still work safely and reliably and cut off the short-circuit current.

    2). Verification based on short circuit conditions is mainly to verify the thermal stability and dynamic stability of the circuit breaker.

Thermal stability means that when the maximum possible short-circuit current passes through the circuit breaker, the heating temperature of the circuit breaker does not exceed its short-term allowable temperature. That is, when the maximum possible short-circuit current passes through the circuit breaker, the circuit breaker will not burn out due to the thermal effect of the current. .

Dynamic stability refers to the maximum possible short-circuit current passing through the circuit breaker, and the circuit breaker will not be damaged or deformed due to strong electric power.

    (3). The rated breaking current of the circuit breaker must be greater than the maximum short-circuit current that may pass through the circuit breaker in the circuit to ensure that the circuit breaker can reliably extinguish the arc.