We usually call lightning arresters T1, T2 and T3. Why do we call them this way? What is the classification of surge protective devices?
The answer is that it is distinguished by its test waveform. These surge protectors perform their respective duties due to their different installation positions, so as to achieve the effect of coordinated use and step-by-step discharge.
1. Class T1 surge protective device is usually considered for its tolerance, which can withstand class I (10 / 350) μ s) The products of waveform impulse test can be represented by T1, and the parameters usually considered are IIMP impulse current value, Zui large continuous operation voltage (UC) and up voltage protection level.
According to the step-by-step weakening mode of lightning protection energy and the insulation and withstand voltage requirements of protection equipment, it is necessary to install T2 and T3 surge protectors for step-by-step or fine protection. The parameters usually considered are: in nominal discharge current, Zui large discharge current (IMAX), Zui large continuous operation voltage (UC) and up protection level.
2. Passed Grade II (8 / 20) μ s) The products of waveform test can be represented by T2;
3. Pass grade III (combined waveform 1.2/50) μ s) Test, its characteristics must be able to withstand (8 / 20) μ s) The product of waveform test can be represented by T3. T3 products are usually used for the protection of terminal fine equipment.