Do you know the location of installing the SPD?
Frequently Asked Questions
Where should SPDs be installed?
SPDs shall at least be installed as close as possible to the origin of the installation.
When should Class I tested SPDs be used?
Class I tested SPDs shall be used when the structure is equipped with an external lightning protection system or protection against effects of direct lightning is otherwise specified. They may also be selected if direct lightning strikes to overhead lines between the last pole and the entrance are to be considered.
When should Class II tested SPDs be used?
Class II tested SPDs shall be used for protection against effects of lightning and against switching overvoltages.
Can additional SPDs be installed downstream?
Yes, additional Class II or Class III tested SPDs may be needed downstream in sub-distribution boards or at socket outlets to sufficiently protect the installation and sensitive equipment.
What is required when using downstream SPDs?
Downstream SPDs shall not be used without SPDs installed at the origin and must be coordinated with upstream SPDs.
What if a Class I SPD cannot provide adequate protection?
If a Class I tested SPD is not able to provide protection, it shall be accompanied by a coordinated Class II or Class III tested SPD to ensure the required voltage protection level.
