Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 17 replies
  • Subscribers 32 subscribers
  • Views 1627 views
  • Users 0 members are here
Options
You may also be interested in
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Surge Protection & Inspection Intervals

PG
If it is considered that an unskilled person could not, safely, replace an SPD surge module;-

Should the recommended interval until the next inspection be shortened if an SPD is part of the Installation (to take into account the limited operating life of the SPD).

If so, are there any guides to the amount of interval reduction?


Regards

PG
  • 0
    Note that SPDs are not one-shot wonders. They will happily zap transients day after day and will typically fail only for a transient that overwhelms them and breaks the built-in fusing device -  e.g. due to a nearby lighting strike.
  • 0
    With a TV, for some years my view has been that if the lightning has jumped goodness knows how many metres from the cloud to your TV aerial, then pulling out the coax plug and leaving it on the carpet is not going to make much difference than leaving connected when the lightning now jumps from that coax plug to your TV...


    If you are detecting the thunderstorm/lightning from the bangs of thunder, don't forget the worst case scenario when the lightning strikes your aerial whilst the metal coax plug is in your fingers...

    Clive
  • 0
    I like the SPD's where the 'flag' operates a set of volt free contacts for this exact reason. A bell transformer and a distinctive buzzer could complete the setup. Some enterprising manufacturer could make a self 'buzzing' SPD for when the industry as a whole starts to fit them routinely.
  • 0
    MHRestorations:

    I like the SPD's where the 'flag' operates a set of volt free contacts for this exact reason. A bell transformer and a distinctive buzzer could complete the setup. Some enterprising manufacturer could make a self 'buzzing' SPD for when the industry as a whole starts to fit them routinely.


    Ditto that.

    I`ll bet nobody does though!


  • 0
    If you want a more accurate  car analogy it is more like the a traction control or diff lock cutting in for a limited number of times - i.e. something that is not needed day to day, and without which the vehicle can be driven normally, but cannot prevent all crashes.


    SPDs that are currently being sold are only effective for a limited range of magnitude of transient- most surge voltages are small and short duration do not start the things conducting at all, and the larger ones that set them conducting permanently are very much one shot events likely to blow the SPD and the still inject surge energy into the following wiring.

    In much the same way that most corners do not need traction control and even on cars with it you might move sideways on black ice.

    Worth fitting when the price point is right, but not generally.

  • 0
    wallywombat:

    Note that SPDs are not one-shot wonders. They will happily zap transients day after day and will typically fail only for a transient that overwhelms them and breaks the built-in fusing device -  e.g. due to a nearby lighting strike.




    Russian roulette?


  • 0
    ebee:
    MHRestorations:

    I like the SPD's where the 'flag' operates a set of volt free contacts for this exact reason. A bell transformer and a distinctive buzzer could complete the setup. Some enterprising manufacturer could make a self 'buzzing' SPD for when the industry as a whole starts to fit them routinely.


    Ditto that.

    I`ll bet nobody does though!




    The original posting queried if the plug-in module of a faulty SPD assembly could   be replaced by an unskilled person and if not, what should the period until the next inspection be quoted on the Installation Certificate or Condition Report.
    I agree with MH Restorations’ & Ebee’s point of view, adding an alarm on SPD failure.
    I’ve checked with a couple of Suppliers and the front of the Consumer Unit has to be removed to change the SPD module. Not a job for an unskilled person.
    The detection of a faulty SPD could be part of a Routine Check in commercial and industrial installations that have formal systems of checking but Domestic premises would be unlikely to have the annual, or shorter, periods recommended in GN3. There are plenty of Forum members who doubt that anyone will ever look at the surge module passive status indication in a domestic installation so it would seem reasonable that BS7671 called for an obligatory audible/visual alarm, say something like a fire alarm bleeping on low battery detection (arrangements are available but don’t seem to be universally adopted).

     


Community Rules & Guidelines