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A question about extension leads

BenCottoBenCotto RutlandPosts: 3,787
Calling out to folk with knowledge of domestic wiring. I have several extension leads in my house. Is there an easy way to identify those which are surge protected from those that are not? Thanks.


  • LiriodendronLiriodendron Scariff, County Clare, IrelandPosts: 7,629
    BS 7671 is the ID which I assume should be printed or embossed on your lead somewhere.  We have one surge protected extension, which is helpfully embossed "Surge protected"...
    "The one who plants trees, knowing that he will never sit in their shade, has at least started to understand the meaning of life."  Rabindranath Tagore
  • Pete.8Pete.8 Billericay, EssexPosts: 9,330
    I have a couple of surge-protected leads I use for my computer related stuff - the only distinguishing feature is that Surge Protected is stamped onto the lead.

    To be honest I'm not sure there's any point in using them - the supply in the UK is stable and such cables would only be beneficial if there was some electrical equipment on your circuit that caused the surge
    Knowledge is knowing that a tomato is a fruit.
    Wisdom is not putting it in a fruit salad.
  • BenCottoBenCotto RutlandPosts: 3,787
    edited September 2020
    Thanks both. We are having our fuse box changed next week and the electrician wants to know if any of our leads are surge protected.

    A job for today is to go round the house looking for the identification marks and removing cobwebs from the plugs behind cupboards and other out of the way corners. My wife has the view we’d be socially ostracised if word got out that our plugs were dirty or dusty!
  • Pete.8Pete.8 Billericay, EssexPosts: 9,330
    I'd guess if you're having a new fuse box it will be one with RCD's which will likely give all the protection you need.
    All extension leads are protected by fuses which are in the plug - it seems a strange question for an electrician to be asking.
    Surge protection is something different, and in my opinion unnecessary.
    Knowledge is knowing that a tomato is a fruit.
    Wisdom is not putting it in a fruit salad.
  • BenCottoBenCotto RutlandPosts: 3,787
    The electrician said surge protected plugs can give false readings when he is doing the testing. I wouldn’t know!
  • Surge protection is different to RCD. RCD is effectively a circuit breaker: it detects ground faults and breaks the circuit. It can also provide surge protection.

    Surge protection on its own (as fitted to those extension cables you can buy) is about smoothing out the "natural" peaks and troughs in an electrical supply current, preventing a momentary over supply even when ground fault doesn't exist. These used to cause problems for electronics, especially older computers, because variances in the current could cause computer psu to blow and damage the equipment inside. However most modern household electronics are now perfectly capable of handling this.

    There are a number of very important rules around the installation and use of delayed or non delayed surge protectors after a consumer rcd. As with everything electrical, the rules change every 2 minutes. So I'm assuming that your electrician is following whatever the relevant IET regulations are, hence his question.

    As to whether you are supposed, or not supposed to use surge protection on a circuit also protected by an rcd, I couldn't tell you as I'm not a qualified electrician!
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