Some lightning protector manufacturers on the market name 4P products as 3PN. 3P+N and 4P circuit breakers are also four-level circuit breakers (consisting of four pairs of input/output terminals). Their difference lies in the zero (N) line terminal. superior.

Among them, some of the 3P+N terminals are straight-through and cannot be disconnected, and some can be disconnected, but the original parts are not protected. Those without protective components may be imported products. Before the 1990s, the direct connection was not disconnected. When wiring, you must pay attention to distinguish the phase line and the zero (N) line, especially for leakage protection circuit breakers, zero (N) ) wire must be accurately connected to this terminal.

The 3PN structure SPD refers to the 3+1 structure surge protector. The SPD protects the three-phase lines to the neutral line and the neutral line to the ground line. It is a full-mode protection.

The material used for the fourth pole of 3P+N is a switch-type material such as a discharge tube or gap. It is a non-voltage-limiting material. According to standard requirements, it is not suitable to use SCB as backup protection.

The N-phase material of the 4P lightning protector is a varistor, which is a voltage-limiting material. During actual use, short circuits will occur and leakage current will occur. Therefore, the surge protector with a 4P structure needs to be equipped with 4P backup protection. protection device. The SPD with a true 3P+N structure only needs to be equipped with a 3P backup protector.

Jinli always provides customers with high-quality, reliable products to achieve long-term and stable growth of the company.

We have a variety of surge protector models for you to choose from, whether graphite gap or varistor. There is always a suitable SPD to meet your requirements.