Many friends don't know much about the functions of 2P, 1P+N, 3P+N, and 4P, and they are very vague.
According to the number of poles, miniature circuit breakers can be divided into 1p, 1p+n, 2p, 3p, 3p+n, 4p and other types, and there are certain differences in the functions and application scenarios of these types of circuit breakers.
1P (Single Pole Circuit Breaker): This circuit breaker only controls the live wire (phase wire), has a thermomagnetic tripping function, and the general module is 18mm. It is suitable for scenarios where only on/off control of the live line is required. However, since it only controls the live wire, if the neutral wire in the circuit also needs to be protected, it needs to be used in conjunction with other circuit breakers.
1P+N (Unipolar+N Circuit Breaker): This circuit breaker controls both the live wire and the neutral wire, but only the live wire has a thermal-magnetic tripping function. When the N line is a non-protective pole or an open and closed neutral pole, the modulus is 2*18mm=36mm (dual mode); When the n-wire is an unbreakable neutral wire, the modulus is 18mm (single mode). It is suitable for scenarios where it is necessary to control both the live line and the neutral line, but the protection requirements of the neutral line are not high. Compared with 1P, the neutral line of 1P+N is not protected and only has an isolation function, while the neutral line of the 2P circuit breaker is protected.
2P (single-phase 2-pole circuit breaker): This circuit breaker controls both the live wire and the neutral wire, and both have the function of thermal and magnetic tripping, and the modulus is 2*18mm=36mm. It is suitable for scenarios where full protection of the live and neutral lines is required. Compared to 1P and 1P+N, 2P provides more comprehensive protection features.
3P (3-pole circuit breaker): This circuit breaker has three terminals, all connected to the live wire, which is suitable for controlling three-phase 380V voltage lines. It is mainly used for the protection of three-phase circuits.
3P+N (3P+N circuit breaker): This circuit breaker adds a control function to the neutral wire on the basis of 3P, (the same as 1P+N) but usually only the live wire has a protection function. It is suitable for scenarios where it is necessary to control both the three-phase live and neutral wires.
4P (4-pole circuit breaker): This circuit breaker has four terminals, three of which are connected to the live wire and one to the neutral wire. It is suitable for controlling three-phase four-wire lines, providing comprehensive protection against three-phase live and neutral lines. Compared to 3P, 4P increases the protection function to the neutral line.