How To Choose A Surge Protector - This Is What Lightning Protection Experts Do
Many friends who are engaged in electrical engineering are confused about the selection of surge protectors, because surge protectors have different levels and specifications, and it is difficult to figure out which specification is more suitable. Today, the editor will interpret the lightning protection zone diagram for everyone. After you understand it, you can easily master the method of rapid selection of surge protectors.
The above is the LPZ lightning protection zone diagram. The concept of lightning protection zones described in the international standard IEC62305-4 has been proven to be reasonable and effective. The basic idea of this theory is to reduce the surge to a harmless level step by step before it reaches the terminal equipment and causes damage. In order to achieve this goal, the entire protection space of the building is divided into several lightning protection zones (LPZs), and surge protectors are installed at the place where the online route enters from one zone to another. The principle of multi-level protection and step-by-step discharge is adopted, and surge protectors of corresponding levels are installed according to the specific requirements of different zones.
According to the LPZ lightning protection zoning diagram, a level 1 (test waveform is Class I 10/350μs) surge protector needs to be installed at the interface between LPZ0A and LPZ1 and between LPZ0B and LPZ1. It needs to have a high discharge current capability to protect the electrical equipment in the building from damage.
A level 2 (test current waveform is Class II 8/20) SPD is installed at the interface between LPZ1 and LPZ2 to further reduce the residual energy of the upstream protection level and limit self-inductance or mutual inductance surges.
Install a level 3 (test waveform is Class III, combined wave, its open circuit voltage waveform is 1.2/50, short circuit current waveform is 8/20) SPD in the area behind LPZ2 for effective and refined protection.
The editor has prepared a detailed surge protector selection table based on the lightning protection zoning. If you need it, please contact us.
