Design Verification when using SPD´s
When using surge protection devices connected in parallel, the switchgear manufacturer does not have to observe any special requirements for verification according to IEC 61439-1. Since the operating current does not normally flow through these surge protection devices, they do not significantly increase the temperature and therefore do not need to be considered separately.
For surge protection devices that carry continuous current and have a series impedance, for example arresters for information technology systems, the power loss data can be calculated using the parameters specified in the data sheets. However, it is important that the specified short-circuit resistance of the surge protection device is at least as high as the short-circuit resistance required at the installation site.
According to the CE declaration of conformity, the surge protection devices are tested in accordance with the relevant product standards such as EN 61643-11, EN 61643-21 and EN 50539-11. The necessary data and information can be found in the data sheets and installation instructions.