How to cooperate with the circuit breaker and isolation switch in the distribution cabinet?
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How to cooperate with the circuit breaker and isolation switch in the distribution cabinet? In the design drawings, the rated current of the circuit breaker is greater than that of the isolating switch, and even the rated current of the isolating switch is greater than that of the circuit breaker? In the design, the isolating switch is installed in front of the circuit breaker. Are there any requirements for current matching? I always feel that the current of the isolating switch should be larger.
Low pressure? high pressure? I have never used a circuit breaker and isolation for low voltage, so I really don’t understand.~
For low voltage, the design institute designed the isolating switch for us and added a circuit breaker. The key isolating switch has a smaller current than the circuit breaker. I don’t understand this. I hope Haiyou can help me.
Isolating switch is a general term. In low voltage, it should be a knife switch, which is used in conjunction with a circuit breaker. As for the current size, the switch and circuit breaker are selected according to the load. The specifications may be inconsistent due to different manufacturers. In other words, you said "the current of the isolating switch is smaller than that of the circuit breaker", but for the load, they should both be large. This is purely my own opinion without any technical basis and is for entertainment only. hehe
The current of the knife switch is slightly larger than the total current of the lower circuit breaker, which is useless at low voltage. Unless the simultaneity coefficient in your low-voltage cabinet is very low, or there is an interlock.