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Scope of Part P (extra-low voltage)

I'm trying to understand the scope of Part P as at the extra low voltage end of things it seems a bit contentious. Below is an extract from Approved Part P and it includes extra-low voltage. That raises some questions:

  1. Would 48V DC be in the scope of Part P as extra-low voltage appears to have no bottom end, just a top end at 50V AC and 120V DC? As an example, installing house wide lighting 'through the fabric of the building' run with a plug in 48V supply (plugged into a socket outlet).
  2. Lots of people are retrofitting under unit lights into their kitchens which are 12V. They have a plug in transformer, but in many cases the wires are then routed 'through the fabric of the building'. Why isn't this in the scope of Part P if a house wide extra-low voltage lighting system would be?

The second case could arguably be an 'electrical installation' too as although it is plugged in to an outlet, the wires and lights are fixed.

Is it that both of these would be in the scope of Part P, but if both plugged in to existing outlets, they wouldn't be notifiable? If that's the case, in theory they could also both have wired in transformers spurred off an existing circuit as that would only be notifiable if it's an 'addition or alteration to existing circuits in a special location' which if it didn't include a bathroom it wouldn't be. Am I understanding that right?

There's a bit of a can of worms here, but LEDs are becoming so efficient that house wide extra-low voltage systems may start to become more of a thing.

Parents
  • I do not consider plugging an appliance into a 13 Amp socket, an addition or alteration to an electrical installation.

    5. Part P notifiable jobs currently include major ones such as house rewires, replacing a consumer unit, and fitting a complete new circuit (for example, for an electric shower or cooker); and alterations in what were deemed the more hazardous locations of kitchens, bathrooms and outdoors. However, alterations elsewhere in a dwelling, and repairs and replacements anywhere, are not notifiable.

    Z.

  • Cheers Z, I don't feel the need to notify anyone when I plug in my laptop daily either. That said, it's not routed through the fabric of the building.

    Do you really feel a full house lighting rewire which converted all the lights to being powered off a 13A socket wouldn't be notifiable?

  • Just who would do that?

    Z.

  • Hello Z.

    Whether notifiable or not is nothing to do with Part P; all work must be done to ensure safety.

    Kitchens and outdoors were in England removed from the notifiable work list in 2013.

  • I do not consider plugging an appliance into a 13 Amp socket, an addition or alteration to an electrical installation.

    OK, so power over Ethernet is powered by something plugged into a socket-outlet.

    But it's over fixed telecomms cabling infrastructure.

    It's definitely part of the electrical installation in the scope of BS 7671. There are also fire and electric shock risks using PoE in bathrooms.

    Whilst it's convenient to try and "get round" Part P, if we are not careful we take ourselves into a world where there are fire (and occasional shock) risks, but there is no way to manage those adequately because there's an opinion forming that it's OK to "scoot around" Part P when it's convenient.

    Yes, it happens all the time, but that doesn't mean the "permanent extension lead" in the garden is safe - and doesn't mean there won't be people in the firing line when something does go wrong and there's a claim or prosecution pending.

    I guess the best person to ask is a solicitor.

Reply
  • I do not consider plugging an appliance into a 13 Amp socket, an addition or alteration to an electrical installation.

    OK, so power over Ethernet is powered by something plugged into a socket-outlet.

    But it's over fixed telecomms cabling infrastructure.

    It's definitely part of the electrical installation in the scope of BS 7671. There are also fire and electric shock risks using PoE in bathrooms.

    Whilst it's convenient to try and "get round" Part P, if we are not careful we take ourselves into a world where there are fire (and occasional shock) risks, but there is no way to manage those adequately because there's an opinion forming that it's OK to "scoot around" Part P when it's convenient.

    Yes, it happens all the time, but that doesn't mean the "permanent extension lead" in the garden is safe - and doesn't mean there won't be people in the firing line when something does go wrong and there's a claim or prosecution pending.

    I guess the best person to ask is a solicitor.

Children
  • I was referring to this

    1. Lots of people are retrofitting under unit lights into their kitchens which are 12V. They have a plug in transformer, but in many cases the wires are then routed 'through the fabric of the building'. Why isn't this in the scope of Part P if a house wide extra-low voltage lighting system would be?

    I consider a few L.E.D. under unit lights on the kitchen wall units powered by an E.L.V. power supply via a 13 Amp plug an appliance, not fixed wiring. Heck, they are supplied as a complete D.I.Y kit.

    You'll be saying a 12 Volt train set power supply, or electric racing car set supplied by a similar transformer is a fixed  installation next.

    Z.

  • What is PoE?

    Z.

  • For cameras the system seems to fail safe.

    https://www.youtube.com/watch?v=LU7T-85EIq8

    Z.

  • Excellent point, I think POE (Power over Ethernet) is a perfect example. Many installations of CCTV involve wires routed through the fabric of the building and installed by DIYers. It plugs into a 13A outlet at one end , but otherwise resembles an electrical installation in every other way (running at ELV).

    It's Part P, but not notifiable (unless you have CCTV in the bathroom, but let's not go there). I expect the average installer wouldn't give Part P a second thought when it came to installing a CCTV system.

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