James asks this question, which concerns whether surge protection is needed to protect external equipment supplies, such as CCTV cameras and lighting columns, from potentially damaging power surges and lightning strike. It has been answered by SELECT (Theme – Power):
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Question: I understand that surge protection should be installed at the mains incomer and locally to key pieces of critical equipment, such as computers. However, is there a requirement provide surge protection on external equipment supplies, such as CCTV cameras and lighting columns etc.?
Answer: Surge protection may be provided as one solution to provide protection against overvoltages due to atmospheric origin or because of switching (see Section 443 of BS 7671:2008 (2011)) where it has been deemed necessary.
It may also be installed as a measure to reduce electromagnetic interference, again where deemed necessary (see Section 444).
There is no specific requirement to provide surge protection!
Where surge protection has been deemed necessary by the designer of the installation, this type of device should be selected and erected as per Section 534.
As you imply in your question, this may be both at the origin of supply and possibly downstream adjacent to sub-distribution equipment, and possibly even locally to equipment where a specific level of protection is desired. The reasons for deeming this type of protection being necessary may be because of the equipment manufacturer’s specification - i.e. manufacturer’s instructions requiring it. Alternatively, it may be necessary because a risk assessment shows that it may be necessary - i.e., if there is a possibility of damage to the equipment by lightning strike, or if the possible consequences of this are severe (loss of life, loss of service, high cost to the building owner etc).
Where lightning protection might be the reason for you considering surge protection, I recommend that you contact Furse, a company that publishes a very useful free guide to BS EN 62305-4. Go to: http://europe.tnb.com/pub/node/1714?r=119 (see link below).
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