Does installing just one surge suppressor at the power receiving end sufficiently protect the equipment?

There is no single answer to this question. If the surge stress at the power receiving end is low in a small facility, installing just one surge suppressor is sufficient. And when installing only one surge suppressor, it is best to install the surge suppressor close to the receiving end. However, large facilities require distributed protection. Here, distributed protection means that surge suppressors for primary protection and secondary protection are installed in the power distribution board and distribution board, respectively.

 

In the following cases, it is recommended to install an additional point-of-use surge suppressor close to the equipment.

* When there is very sensitive equipment such as electronic equipment or computers

* When the equipment to be protected is too far away (more than 30m) from the surge suppressor.

* When an electromagnetic field is formed within a building due to lightning, etc.

When installing a surge suppressor, you must consider the voltage that your most sensitive equipment can withstand. The surge suppressor closest to this equipment must limit the surge voltage to less than 80% of the voltage (Uw) that the equipment can withstand. Therefore, if the limiting voltage of the first surge suppressor is less than 80% of Uw, there is no need to install a second surge suppressor.

If equipment is far away from the surge suppressor, oscillation occurs in the line, and as a result, the voltage applied to the terminals of the equipment to be protected may exceed twice the surge suppressor's limiting voltage. In this case, the equipment may be damaged even though a surge suppressor is installed. However, at distances of less than 10 m, oscillation can be ignored.

Additionally, it is a good idea to not only protect the power panel but also install a multi-service SPD. Multi-service SPD has great effectiveness by connecting all various lines, such as power lines and telephone lines, entering the facility to the same ground.