When selecting level 3 and level 4 circuit breakers, the first thing to consider is the load type and load size. Generally speaking, the three-level circuit breaker is suitable for occasions with relatively small power load, and the four-level circuit breaker is suitable for occasions with relatively large power load. Therefore, when selecting, it is necessary to analyze the load situation in detail and choose according to the actual demand.
We also need to consider the magnitude of short-circuit current. According to the national standards, the maximum short-circuit current that different grades of circuit breakers can withstand is also different. Therefore, when selecting, it is necessary to calculate the maximum short-circuit current that may occur in the system according to the actual situation, and select the circuit breaker that can withstand the short-circuit current.
We also need to consider the influence of the service environment on the circuit breaker. For example, environmental temperature, humidity, corrosiveness and other factors will affect the service life and safety of circuit breakers. So the choice needs to be adjusted according to the use environment.
When selecting level 3 and level 4 circuit breakers, many factors need to be comprehensively considered and selected according to actual needs.
Regarding whether there is a regulation, the relevant national standards clearly stipulate the maximum short-circuit current of circuit breakers of different grades. Therefore, when purchasing, we must choose according to national standards to ensure the security and stability of the system.
The selection of Class 3 and Class 4 circuit breakers needs to comprehensively consider many factors such as load type, load size, short-circuit current, use environment, etc., and choose according to national standards to ensure the safety and stability of the system.