Must-have catalogue from Wylex helps installers insure against transients

04-03-2014

Wylex has published a catalogue of Surge Protection Devices (SPDs) that includes advice on, BS7671 requirements and alternatives to AQ criteria, plus an easy to follow selection chart / flow diagram that provides a simple overview of selection criteria to assist installers in protecting installations against transients - short, pulse like, voltage peaks with steep rising edges.

This valuable document also explains the causes of these surge voltages e.g. from lightning strikes, or internal e.g. switching and advises which type of device is needed for typical situations.

The first line of defence for vulnerable structures is always a Lightning Protection System, designed to capture and safely conduct away to earth discharge current. Additionally, at the intake position of the associated electrical installations, the correct Wylex Type 1 Lightning Arresters should be installed. The Wylex surge arresters listed in the new catalogue have a high impulse current withstand (10/350μs) typical of the conditions resulting from direct lightning strikes.

The secondary effects of lightning strikes can account for some of the most extreme forms of transient overvoltage and the subsequent damage to an electrical installation and connected equipment. Wylex Type 2 Surge Arresters provide protection while also protecting against internal overvoltage originating from switching. Type 2 devices will discharge current having an 8/20μs waveform and provide a low voltage protection level of ≤1.5kV (Up) for sensitive electronic equipment exceeding the requirements for category II equipment identified within table 44.3 (BS7671).

Wylex lightning and surge arresters can be provided as an integral part of many single phase NH consumer units with Type 2 surge protection connected at the main switch. Wylex Panelboards also can include a range of catalogued lightning and surge arrester kits that enable on site customization of this commercial distribution system. Type 1, 2 and 1+2 devices can be applied and mounted integrally within the framework of any Wylex Panelboard. All necessary steelwork and interconnections are included within the relevant SPD kits.

The new SPD catalogue lists the complete range of Wylex surge arresters together with a handy flow diagram listing typical installations and the suggested protection and is available to download from www.electrium.co.uk/WylexSPD.pdf or by calling Wylex sales on +44 1543 455000