Discover the 4 key steps to choosing the perfect surge protection device (SPD) for your needs and effectively protect your building from lightning and surge damage. You will need the following information about the installation:
Below, we provide you with a guide to help you select the right surge protection device and offer your building the best possible protection.
The first step is to determine the lightning protection level. There are four lightning protection levels:
Lightning impulse current [Iimp]: 200 kA
Application example: Ex-zones
Lightning impulse current [Iimp]: 150 kA
Application example: Hospital
Lightning impulse current [Iimp]: 100 kA
Application example: Residential home
The lightning protection levels estimate different heights of lightning currents against which protection is to be provided:
This diverts 50% of the lightning current to earth, while the other 50% is conducted into the building. These are distributed throughout the wiring system to all active conductors and can cause damage to the building. For a building in lightning protection level III and a TN-S network (5-conductor), this results in a required Iimp of 10 kA for surge protection.
Did you know that 80% of buildings comply with lightning protection level III? Find out more about lightning protection levels here:
As an electrician or installer, you then decide where the lightning and surge protection should be installed. In the main power distribution, use either a type I (external lightning protection available) or type II (no external lightning protection available), while a type II SPD is sufficient in a sub-distribution.
Next, you must check the connected grid system. A TN-C grid requires three-pole surge protection (3+0), while a TN-S grid requires four-pole surge protection (e.g. 3+1).
Finally, use the mains voltage to determine the voltage level of the SPD and ensure that your protection device is precisely tailored to your needs. In Europe, for example, the mains voltage is 230/400 V. For this mains voltage, you need 230 V lightning and surge protection.
