The Difference Between Surge Protector and Lightning Arrester

Lightning arresters and surge protective devices, as commonly used components in electrical equipment, have the function of preventing overvoltage, especially lightning overvoltage, but there are still many differences in the application of the two. Today we will introduce the specific differences between these two types of products.

1. The difference between the application field of surge protective device and lightning arrester in terms of voltage level

The rated voltage of the arrester is from ﹤3kV to 1000kV, and the low voltage is 0.28kV and 0.5kV. The rated voltage of the surge protective device is ≦1.2kV, 380, 220~10V~5V.

2. The protection objects of surge protective device and lightning arrester are different

Surge arresters protect electrical equipment, while SPD surge protective devices generally protect secondary signal circuits or power supply circuits for electronic instruments and meters.

3. The insulation level or withstand voltage level of the surge protective device and the lightning arrester are different

The withstand voltage level of electrical equipment and electronic equipment is not on the same order of magnitude, and the residual voltage of the overvoltage protection device should match the withstand voltage level of the protected object.

4. The installation positions of surge protective device and lightning arrester are different

Surge arresters are generally installed on the primary system to prevent the direct intrusion of lightning waves and protect overhead lines and electrical equipment; while SPD surge protective devices are mostly installed on the secondary system after the arrester eliminates the direct intrusion of lightning waves, or the arrester There are no supplementary measures to eliminate the lightning waves; therefore, the arrester is mostly installed at the incoming line; the SPD is mostly installed at the end of the outgoing line or at the signal circuit.

5. The flow capacity of surge protective device and lightning arrester is different

Because the main function of the arrester is to prevent lightning overvoltage, its relative current capacity is relatively large; for electronic equipment, its insulation level is much lower 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. The SPD is generally at the end and will not be directly connected to the overhead line. After the current limiting effect of the upper level, the lightning current has been limited to a lower value, so that the SPD with a small current capacity can fully play a protective role. It doesn't matter, what matters is the residual pressure. For effective protection against lightning overvoltage and operating overvoltage, it is crucial to use both surge arresters and SPD surge protective devices manufactured by a reputable surge protection devices manufacturer. 

6. Surge protectors and lightning arresters are made of different materials

The main material of the arrester is mostly zinc oxide (one of the metal oxide varistors), and the main material of the surge protective device is different according to the anti-surge level and graded protection, and the design of lightning surge protection devices is more precise than ordinary lightning arresters.

7. The difference between the surge protective device and the lightning arrester from the nominal discharge current

The surge arrester index discharge current In is from 1.5kV, 2.5kV, 5kV, 10kV, 20kV. 8/20us nominal lightning current, surge protective device nominal discharge current from 5kA, 10kA, 0.5kA, 20kA, 30, 20, 120kV.

8. Differences between surge protective devices and lightning arresters

Surge arresters are mainly used in power stations, lines, distribution stations, power generation, capacitors, motors, transformers, iron and steel smelting, and railways. Surge protectors are mainly used in low-voltage power distribution, cabinets, low-voltage electrical appliances, communications, signals, machine stations, and machine rooms.