Lightning arrester is a device that protects equipment from lightning shock waves in substations. When the lightning shock wave introduced into the substation along the line exceeds the protection level of the arrester, the arrester discharges first, and the lightning current is safely introduced into the earth through a good conductor. The grounding device is used to limit the lightning voltage amplitude to the lightning impulse level of the protected equipment, so that Electrical equipment is protected.
Surge Suppressors, also known as lightning protection device, abbreviated as (SPD), is suitable for AC 50/60HZ, rated voltage 220V to 380V power supply system (or communication system), to indirect lightning and direct lightning influence or other transient overvoltage electricity Surge Suppressors is suitable for the requirements of Surge Suppressors in households, tertiary industries and industrial fields. It has phase-to-phase, phase-to-earth, phase-to-neutral, neutral-to-earth and combinations of protection modes.
The rated voltage of the arrester ranges from 3kV to 1000kV, low voltage 0.28kV, 0.5kV. The rated voltage of the Surge Suppressors is less than 1.2kV, 380, 220~10V~5V.
Lightning arresters are used to protect electrical equipment, while SPD Surge Suppressors generally protect secondary signal circuits or power supply circuits at the end of electronic instruments and meters.
The withstand voltage level of electrical equipment and electronic equipment is not in the same order of magnitude, and the residual voltage of the overvoltage protection device should match the withstand voltage level of the protected object.
Lightning arresters are generally installed on the primary system to prevent the direct intrusion of lightning waves and protect overhead lines and electrical equipment; SPD Surge Suppressors are mostly installed on the secondary system, after the lightning arrester eliminates the direct intrusion of lightning waves, or lightning arresters There is no supplementary measure to eliminate the lightning wave; therefore, the lightning arrester is mostly installed at the incoming line; the SPD is mostly installed at the end outlet or signal circuit.
Because the main function of lightning arrester is to prevent lightning overvoltage, its relative current capacity is relatively large; for electronic equipment, its insulation level is much smaller than that of electrical equipment in the general sense, so SPD is required to protect against lightning overvoltage and operating overvoltage. But its flow capacity is generally not large. (SPD is generally at the end and will not be directly connected to the overhead line. After the upper level of current limiting, the lightning current has been limited to a lower value, so that the SPD with a small current capacity can completely protect it. Value is not important, what is important is residual pressure.)
The power Surge Suppressors has a large distance between the terminal equipment and the front-level Surge Suppressors, which makes the line easy to produce oscillation overvoltage or induce other overvoltages. It is suitable for the fine power Surge Suppressors of terminal equipment, and the protection effect is better when used in conjunction with the front-level Surge Suppressors.
The main material of the arrester is mostly zinc oxide (a kind of metal oxide varistor), and the main material of the Surge Suppressors is different according to the anti-surge grade and the graded protection (IEC61312), and the design is better than the ordinary one. The mine is much more precise.
Surge arresters cannot reach the level of Surge Suppressors in terms of response time, pressure limiting effect, comprehensive protection effect, and anti-aging characteristics.