Furse - Lightning & Transient Over-Voltage Protection
Lightning Protection Standards - Effective Earthing - BS EN 62305 - Overvoltages
Total Solution to Lightning Protection, Earthing & Transient Overvoltage Protection Requirements
From design advice to innovative, solution-oriented products, Furse has the expertise, experience and excellence to provide a Total Solution to your individual lightning protection, transient overvoltage and earthing problems.
Lightning Protection Standards
BS EN 62305 replaced BS 6651 in 2008, and, following on from the IEC (World) and CENELEC (European) versions of IEC/EN 62305, is the recognised standard for lightning protection.
BS EN 62305 is a four part standard consisting of General principles; Risk management; Physical damage to structures and life hazard; and Electrical and electronic systems within structures. Additionally, it includes the requirements of the BS EN 62561 series of standards, which is the ratified European standard relating to the capabilities of lightning protection components.
BS EN 62305 Part 1 is an introduction to the other parts of the standard and essentially describes how to design a Lightning Protection System (LPS) in accordance with the accompanying parts of the standard.
BS EN 62305 Part 2 risk management is a very detailed approach to the risk of lightning inflicted damage to structures, their contents (electronic equipment) and living beings. It identifies different risk components that collectively are compared to a tolerable risk. It is a very long-winded process when carrying out the assessment long hand. A computer program is commercially available from Furse to considerably reduce the time to implement the risk procedure.
BS EN 62305 Part 3 relates directly to the major part of BS 6651. It differs from BS 6651 in as much that it has four classes or protection levels of Lightning Protection System (LPS), as opposed to the basic two (ordinary and high-risk) levels in BS 6651.
BS EN 62305 Part 4 covers the protection of electrical and electronic systems housed within structures. This part essentially embodies what annex C in BS 6651 detailed, but with a new zonal approach referred to as Lightning Protection Zones (LPZ). It provides information for the design, installation, maintenance and testing of a Lightning Electromagnetic Impulse (LEMP) protection system for electrical / electronic systems within a structure.
To assist with customer concerns, we offer a design and advisory service for lightning protection to IEC/BS EN 62305.
Structural Lightning Protection
It is vital that buildings are designed and equipped with a lightning protection system that will ensure the safety of the structure and its occupants. Given the importance of bonding and proper connection of the components of the Lightning Protection System (LPS), just one faulty or poor quality component can lead to costly damage, even fatalities.
Furse lightning protection products are designed and manufactured to the highest standards. Primary in our range are our conductors – in flat tape, solid circular and stranded format, copper and aluminium, many of which can be PVC coated for greater aesthetic appeal.
Furse also offer a large range of air terminals, fittings, bonds, clamps and lightning current / equipotential bonding Surge Protection Devices (SPDs). In accordance with BS EN 62305, these SPDs are required where direct connection with bonding conductors is not suitable – for example metallic power and telecommunication lines.
The dangers posed to both life and equipment by poor earthing make effective earthing essential. Given the complexity of national and international standards in earthing system design, material specification and installation, it makes sense to talk to Furse.
Furse design and model earthing electrode systems in compliance with BS 7430, IEEE standard 80, BS EN 50522, ENA TS 41-24 and other accepted standards. The comprehensive Furse range of earthing equipment includes: solid copper, stainless steel and copperbond earth rods and accessories; high copper alloy bonds and clamps; earth pits, solid copper plates, lattice mats, earth rod seals and the FurseWELD exothermic welding system.
Electronic Systems Protection
BS 6651 had an informative annex C giving the reader recommendations on the implementation of Surge Protection Devices (SPDs). BS EN 62305 now has transient overvoltage protection as an integral part of the standard (BS EN 62305-4), governed by the single risk assessment of BS EN 62305-2. Where required by BS EN 62305, SPDs shall be selected and installed in accordance with the IET Wiring Regulations (BS 7671:2008 +A1:2011, Section 534).
Even with the best available structural lightning protection, the electrical and electronic contents of a building are at risk from the secondary effects of lightning – transient overvoltages. Lightning activity can create sub-millisecond transient overvoltages of up to 6,000 V on power, data, signal and telephone lines. Transients destroy, damage or degrade the electronic components of the equipment through which they pass on their route to earth. Transients can also occur on mains power supplies within the building through electrical switching events. Any piece of equipment incorporating electronic components is at risk: from computers and PBX to fire alarms and even Uninterruptible Power Supplies.
To prevent transient damage, SPDs should be fitted on all metallic power, data communication, signal and telephone lines where they enter or leave a building. The Furse ESP range includes SPDs for most applications, including mains power, data or signal lines, telephone lines, CCTV/CATV video cables, coaxial RF lines and Ethernet networks.
Detailed technical guidance is available from Furse engineers in Nottingham, and our field-based engineers can provide site surveys and protection proposals.
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