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Surge Protection
SURGE PROTECTION & THE NEW STANDARD Introduction Under BS 6651 details of surge protection were contained in annex "C" of the document and hence was not part of the main standard. As a result the area of surge protection was considered to be advisory in the design of a lightning protection system. Under IS EN 62305 surge protection has been incorporated in to the main part of the document and hence one can no longer have a full lightning protection system without the inclusion of surge protection. This inclusion of surge protection into the main document has created a problem within the industry. The problem of surge protection devices (SPDs) raises its head in the following areas
Design The problem here is who designs the surge protection device (SPD) layout. As a contractor (primarily) ADS rarely have the level of information required at tender stage to design the layout of an SPD system and therefore ADS believe that this task lays firmly with the consultant. Installation The panel builders will no doubt install SPDs on the panels. However, these may not be sufficent under the new standard. Although any of the parties involved (main contarctor, electrical contractor, lightning protection contarctor) can phyisically fit SPDs the real problem is warranty Warranty The nature of wiring, in any building, is that no one party is responsible for the entire fit out. There are contractors, panel builders and plant/component installers. Therefore, should another party fit an SPD to another parties utility, this, no doubt, will negate any and all warranties that come with the utility ie panels and or lines. In effect the SPDs could become an "out" for the the party concerned. This is a problem for any SPD installer, regardless of who they are in the contractual food chain, and or of their skills. As mentioned before ADS can fit SPDs to a building phyisically but this would create problems in terms of warranty. Shell And Core Projects The above outlines the problems the new standard has created for a straight forward "start and finish" project. Where ADS believes the new standard really falls down is when one considers a "shell and core" project. In this senario the end use of the building is not predetermined and hence the finished electrical fit out is not known, either in magnitude or design. Therefore such a structure can be externally protected and have a warrenty negating SPD to the incomming panel, but the real problem occurs when a client moves into the structure. Not only will they not have warrenties for the incomming panels, but the end use of the building may negate the entire lightning protection system. It is at this point that the client/consultant must be aware that the building will have to reassessed under the risk assessment, as set out in the standard, to determine if the end use of the building is covered by the existing LPS. Also at this point, the client needs to be aware that further SPDs maybe required. This is something that ADS feels the client/consultant and the electrical contractor needs to be aware of should such a senario arise and not assume that, because the building has lightning protection, so does the proposed end use. Conclusion ADS perform risk assessments to IS EN 62305 (and can also perform risk assessments to BS EN 62305) on all structures when designing a lightning protection system (LPS) and therefore can inform on the level of protection and the type of SPD system the proposed building should have. As a result of the probelms outlined above ADS are reluctant to install SPDs to a structure, believing that this is an area to be addressed by the consultant and or the electrical contractor, as they are the parties that [a] have all the information at tender stage and [b] design the wiring layout and have an input/influence in the design of the panels. As a result ADS provides certification of its designs and installations to Part 3 of the standard only, ie the part of the standard that deals with the external lightning protection.
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