Surge Arrester Parameters

How to Choose the Right Surge Arrester

One of the most important steps in protecting your facility from lightning and overvoltage is selecting the correct surge arrester. To make the right selection, it is essential to understand the meaning of surge arrester parameters. By knowing these parameters, you can choose the proper surge arrester for your system.

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1- Uc Operating Voltage

Uc operating voltage is the maximum continuous voltage that can be applied to the surge arrester without damage. It should be calculated as an RMS value.

2- Ut Temporary Overvoltage

Ut temporary overvoltage is the maximum voltage the surge arrester can withstand for 5 seconds without damage. In most cases, this value is equal to or higher than the Uc operating voltage.

3- Discharge Current (In and Imax)

Maximum discharge current Imax is the highest current that Type 2 surge arresters can withstand on an 8/20 μs waveform without damage.

Nominal discharge current In is the pulse current that Type 1 and Type 2 surge arresters can carry without damage. They can withstand this pulse 15 times consecutively.

4- Impulse Current Iimp

Impulse current is the current that Type 1 surge arresters can withstand on a 10/350 μs waveform (lightning pulses) without damage.

5- Up Protection Level

Up, or maximum protection voltage, is the voltage present on the surge arrester while it conducts nominal discharge current to the ground. The lower this value, the better the protection. According to IEC 60364, for 230/400 V inputs, a Up value of 2.5 kV is recommended, while for protecting electrical/electronic equipment, a value of 1.5 kV is recommended.

For surge arrester selection, installation, and applications, you can contact Yıldırımdan Korunma Merkezi.