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Understanding of Breaking Capacity Parameters of Molded Case Circuit Breakers


The breaking capacity is generally represented by uppercase letters. The breaking capacity represented by each manufacturer's letter is different. The details are subject to the manufacturer's selection sample. Let us give two examples, a joint venture brand and a domestic brand.

Take Schneider's NSX series switch as an example: its breaking capacity is E 16kA, B 25kA, F 36kA, N 50kA...

For example, Chint's NM1 series switch has a breaking capacity of S 35kA, H 50kA, and R 85kA;

Here we need to emphasize that no matter whether it is a joint venture brand or a domestic brand, the naming method of each manufacturer is different, and the breaking capacity value represented by each letter is also different, including the same series of switches, such as NM1-125S/ 3300 125A switch, S represents the breaking capacity is 35KA, NM1-400S/3300 225A switch S represents 50KA,

The breaking capacity of most manufacturers is reflected in the form of letters in the model, but there are also differences, and the manufacturer's manual shall prevail for details;

In addition, the breaking capacity we often talk about generally refers to the ultimate short-circuit breaking capacity. Sometimes some technical specifications require limited short-circuit breaking capacity and operating short-circuit breaking capacity. Pay attention when selecting models.

Another point is that the breaking capacity of the circuit breaker corresponding to the different rated voltage is different. The rated voltage of the commonly used circuit breaker is generally 240V, 380V (415V), 690V, etc., so the breaking capacity corresponding to the same model and different rated voltage is also different. the same. This video will be shared here. If you have any other questions, please leave a message and exchange. Thank you for watching. Goodbye.