BS:EN 62305-4 sets out the rules for applying surge protection devices (SPDs) to protect the contents of the building from the secondary effects of lightning, and from internally generated switching transients.
Should the risk assessment dictate that a structural Lightning Protection System (LPS) is required, the system designer should always fit equipotential bonding Surge Protection Devices (SPDs). These are referred to as Lightning Current Arresters in our product selection pages.
If the assessment dictates that an LPS is not required, but there is an indirect risk that electrical services entering the structure could be affected, the designer should always fit SPDs.
A Lightning Protection system that employs the use of “structural Lightning Protection/Earthing” alone does not effectively protect electronic systems.
Effective protection is only achieved through the use of “coordinated SPDs”:
Type 1: lightning current arresters (tested with a 10/350μs waveform)
Type 2: surge arresters (tested with an 8/20μs waveform)
Type 3: surge arresters, fine protection (tested with an 8/20μs waveform)
BS:EN 62305-4 employs a principle of using Lighting Protection Zones (LPZ) to progressively reduce a potential 6,000 volt transient overvoltage to a safe voltage below that of the withstand voltage of the equipment to be protected. SPDs are located at the boundaries of these zones.
Kingsmill offer combined Type 1 + 2 SPDs as an easy and economical choice.
Kingsmill Surge Protection Devices are set out in the Surge Protection section.