Lightning & Surge Protection – An Introduction

Lightning and Surge Protection for electronic systems to the new* British and European standard BSEN62305-4: Surge Protection Devices Ltd offer the complete solution to protect vital systems from damage.

Recently introduced standards put equal importance on protecting the electrical installation and electrical equipment as to the building itself.

Modern micro electronic components are very sensitive to overvoltages and because many systems are networked they rely on each other for the system to operate. If one part of the system gets damaged due to lightning or surges, the whole system won’t operate. The consequential losses suffered during such events i.e. downtime and lost production, can be very high.

We offer a wealth of experience in helping to decide which product best suits your needs. Our website contains our most popular products, however we have many more products and components to suit a range of applications.

*New standard BSEN62305-4 1st September 2008 and 18th Edition Wiring Regulations 1st January 2018.

The New BSEN62305-4 Standard Explained

This new standard replaced BS6651 on 1st September 2008, and it is now mandatory to fit a lightning current arrester on main incoming panels which are situated in buildings with external lightning conductors or fed by an overhead line. This type of arrester is designated as a Type 1, we recommend a combined Type 1+2+3 arrester as this gives additional surge protection for no added cost. The minimum discharge capability for a Type 1 arrester has to be 50kA 10/350µs.

Panels or sub-distribution boards feeding external circuits such as car park lightning, CCTV etc. should also have a combined Type 1+2+3 arrester fitted as standard.

For panels and sub distribution boards in buildings without external lightning conductors and fed by underground cables a Type 2 surge arrester is sufficient. Sub-distribution boards or local control panels more than 10 metres from the main incomer and not feeding external circuits, a Type 2 surge arrester can be used.

Final sub-circuits and sensitive electronic equipment eg. Fire/Burglar alarm panels and PLC’s which are fitted more than 10 metres from the last surge arrester should have a Type 3 surge arrester fitted at the panel or equipment to be protected.