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Which bits of domestic wiring does BS 7671 cover?

AJJewsbury
As BS 7671 has been gradually extending its scope over the years, so we're now just about at the point that it covers any electrical installation that isn't specifically covered by another (BS?) standard (to paraphrase section 110) - and specifically mentions communication, signalling and control fixed wiring. So I'm trying to figure out what standards apply to what:


A few examples:
  • Power and lighting - yes, I'm happy that's just BS 7671.

  • Phone cabling - comes under BS 6701 that seems clear enough (maybe in addition to BS 7671, but there's room for deviation from BS 7671 demands all the same)

  • ELV intruder alarm wiring - I've come across BS EN 50131 series but can't tell (without paying a fortune) whether that covers just individual components or also acts as an installation standard - anyone know?

  • Fixed speaker wiring (say from a wall or ceiling speaker to 4mm sockets/binding posts on the wall behind the hifi)

  • UHF co-ax (i.e. TV aerial/satellite)

  • LV control wiring for CH systems (I'm guessing this is BS 7671 although every EICR I see seems to suggest otherwise)

  • Likewise similar wiring - e.g. pump/valves for solar thermal systems, air-con or heatpumps.

  • ELV heating control wiring (e.g. from 12V 'network' type room 'stats to underfloor heating manifold controllers)

  • Structured cabling (CAT 5 kind of thing) - usually done to TIA/EIA-568 - am I right in thinking that BS EN 50173 is equivalent?


Anyone know of some standards that would apply to these instead of (or in addition to) BS 7671? Or on paper at least, should I be looking to find sheathed speaker cables, IP2X binding posts and a suitable 30mA RCD for when they're concealed in the wall (as far as I can tell the amplifier isn't a SELV source), intruder alarm contacts that don't rely on the timber door frame to complete the enclosure, or co-ax that complies with BS 5467, 6724, 7846, 8436 or 60702-1? ?


   - Andy.
  • 0
    Hi Andy

    I particularly dislike the feature creep here, BS7671 should be "mains voltage" (and perhaps SELV etc) wiring only, because it is very poor and over prescriptive in many other areas, like electronic wiring and data infrastructure. The worst part is the idiotic attempt to cover energy efficiency, which is presumably still being pressed by the IEC and Europe, who seem fixated with "green" issues.
  • 0

    davezawadi:

    ...The worst part is the idiotic attempt to cover energy efficiency, which is presumably still being pressed by the IEC and Europe, who seem fixated with "green" issues.




    I'm glad I'm not alone in thinking that  section 8...or rather appendix whatever it is, is totally pointless... It's not that I don't want to be green, it's just that BS 7671 is the wrong place for that and what is written in BS 7671 is total waffle..

  • 0

    AJJewsbury:

    As BS 7671 has been gradually extending its scope over the years, so we're now just about at the point that it covers any electrical installation that isn't specifically covered by another (BS?) standard (to paraphrase section 110) - and specifically mentions communication, signalling and control fixed wiring. So I'm trying to figure out what standards apply to what:


    A few examples:



    • Power and lighting - yes, I'm happy that's just BS 7671.

    • Phone cabling - comes under BS 6701 that seems clear enough (maybe in addition to BS 7671, but there's room for deviation from BS 7671 demands all the same)

    • ELV intruder alarm wiring - I've come across BS EN 50131 series but can't tell (without paying a fortune) whether that covers just individual components or also acts as an installation standard - anyone know?

    • Fixed speaker wiring (say from a wall or ceiling speaker to 4mm sockets/binding posts on the wall behind the hifi)

    • UHF co-ax (i.e. TV aerial/satellite)

    • LV control wiring for CH systems (I'm guessing this is BS 7671 although every EICR I see seems to suggest otherwise)

    • Likewise similar wiring - e.g. pump/valves for solar thermal systems, air-con or heatpumps.

    • ELV heating control wiring (e.g. from 12V 'network' type room 'stats to underfloor heating manifold controllers)

    • Structured cabling (CAT 5 kind of thing) - usually done to TIA/EIA-568 - am I right in thinking that BS EN 50173 is equivalent?


    Anyone know of some standards that would apply to these instead of (or in addition to) BS 7671? Or on paper at least, should I be looking to find sheathed speaker cables, IP2X binding posts and a suitable 30mA RCD for when they're concealed in the wall (as far as I can tell the amplifier isn't a SELV source), intruder alarm contacts that don't rely on the timber door frame to complete the enclosure, or co-ax that complies with BS 5467, 6724, 7846, 8436 or 60702-1? ?


       - Andy.

     




    Do you need to add fire engineering?  I think that is where the IET were going with the poorly worded regulation recommendation fro the application of AFDDs! ;)

  • 0
    Well, speakers may be driven by amplifiers that claim to be capable of delivering the best end of a kilowatt into 4 or 8 ohms, so there is scope for injury as if could be more than 50V RMS, you could even play a 50Hz tone.....

    Actually I have (mis) used a really big audio amp that was not rated in 'music watts'  to  test equipment at non-50Hz frequencies  quite successfully, stepping up to mains-like volages via a large 12-0-12  transformer and adjusting the tappings and the volume to suit.

    But I agree, there is enough trouble with a one size fits all standard for mains wiring when you have mains logic for the hot water and so on, without trying to define how doorbells, power over ethernet  and fariry lights should be wired in the same document. If the jam is spread too thinly the desired effect is lost.

    It would be better if it stopped at standard mains wiring.

  • 0
    Yes, but whilst 110.1.2 seems to capture all circuits (up to 1000 V AC (i) ) and other wiring systems and cables (iii) and other fixed wiring (v) it seems to be pretty limited in the details e.g. proximity to other services 528.


    We don't seem to have come to any harm when the installer put the mains cable, speaker cables, and another connexion is the same sleeve in order to keep it neat and tidy, but that lot is out of scope in any event.
  • Former Community Member
    0 Former Community Member
    Best ask a PAT guy as they tend to consider the oven, hob etc as part of the fixed wiring guy's EICR!


    Regards


    BAD
  • 0
    As a bit of a 'jack of all trades and master of a couple' (I have been an electrician for 30 yrs ...dear lord already?) and also trained in data and telecomms (back in the 2400baud is fast days) I think the feature creep could be helpful, to encourage knowledge of other systems, but it needs to be better directed. Explaining WHY running mains alongside your cat6 gigabit network cable is a bad idea, rather than just proscribing it completely for example. I am happy to deviate from bs7671 in terms of separation on a simple crossover of mains and say a network cable... because to me, there's no conceivable fault that could cause the 240v to appear on the LAN without the building already being on fire or being attacked by hans gruber. And ethernet transformers (found in every proper ethernet termination) are capable of dealing with it anyway.  With phone lines, it's a greyer area... they extend outside the building and you might zap an openreach person. But the total lack of understanding I see every day from general trades, needs to be countered
  • 0

    AJJewsbury:

    As BS 7671 has been gradually extending its scope over the years, so we're now just about at the point that it covers any electrical installation that isn't specifically covered by another (BS?) standard (to paraphrase section 110) - and specifically mentions communication, signalling and control fixed wiring. So I'm trying to figure out what standards apply to what:


    A few examples:




    All of the below, see 110.1.3 for further details.




    • Power and lighting - yes, I'm happy that's just BS 7671.


    Well, not quite, BS 7671 + BS 5266 and BS EN 1838 for emergency lighting


    • Phone cabling - comes under BS 6701 that seems clear enough (maybe in addition to BS 7671, but there's room for deviation from BS 7671 demands all the same)


    BS 6701 reinforces or augments BS 7671 requirements. There are no "conflicts". BS 6701 actually refers to BS 7671 as a requirement.


    • ELV intruder alarm wiring - I've come across BS EN 50131 series but can't tell (without paying a fortune) whether that covers just individual components or also acts as an installation standard - anyone know?


    A bit of both, but the general cabling is ICT cabling and BS 6701 (and the standards it references) covers that oo.


    • Fixed speaker wiring (say from a wall or ceiling speaker to 4mm sockets/binding posts on the wall behind the hifi)


    BS 7671 alone really. The equipment is covered by BS EN 62368-1 (which replaces BS EN 60065).


    • UHF co-ax (i.e. TV aerial/satellite)


    BS 7671 + BS EN 60728-11 + BS 6701 (as it's ICT cabling). Whilst this is not listed specifically in Regulation 110.1.3 of BS 7671, BS EN 60728-11 refers specifically to IEC 60364-series of standards (which are implemented in the UK as BS 7671).


    • LV control wiring for CH systems (I'm guessing this is BS 7671 although every EICR I see seems to suggest otherwise)


    BS 7671 + standards referenced from BS 6701 (as it's ICT cabling)


    • Likewise similar wiring - e.g. pump/valves for solar thermal systems, air-con or heatpumps.


    Likewise.


    • ELV heating control wiring (e.g. from 12V 'network' type room 'stats to underfloor heating manifold controllers)


    And again.


    • Structured cabling (CAT 5 kind of thing) - usually done to TIA/EIA-568 - am I right in thinking that BS EN 50173 is equivalent?


    This is definitely covered by BS 7671 + BS 6701.

    Anyone know of some standards that would apply to these instead of (or in addition to) BS 7671? Or on paper at least, should I be looking to find sheathed speaker cables, IP2X binding posts and a suitable 30mA RCD for when they're concealed in the wall (as far as I can tell the amplifier isn't a SELV source), intruder alarm contacts that don't rely on the timber door frame to complete the enclosure, or co-ax that complies with BS 5467, 6724, 7846, 8436 or 60702-1? ?


       - Andy.

     






    I feel your pain on the RCD issue, I have raised this a number of times ... but a good question that everyone appears happy to ignore. The intruder alarm contacts will comply with a relevant standard. Perhaps more tricky may well be whether the panel is providing SELV/PELV or not, especially when BS EN 62368-1 takes over from BS EN 60950-1 and BS EN 60065, as the new standard has completely abandoned the concept of SELV and PELV !!!

  • 0
    It's is interesting to see that a whole group of standards are attempting to specify wiring. This is precisely what is wrong! I don't know exactly who keeps adding all these others, but it is probably the same group who tried to control kettle and toaster power to save energy! There should be one standard only for each area, because otherwise they try to specify differing versions of pretty much everything, the result being that none of them are useful and simply give lawyers something to cause trouble and doubt the "evidence". All jobs for the boys, but not that which a proper system should either encourage or allow. It is in most cases simply scope creep by those who don't know or care or just want power over others.


    This kind of thing happens in all areas of "standards", if its not in one place it is not really very useful is it? BTW audio amplifiers which give 10kW into 8 Ohms are not unknown, but I have never heard of anyone getting a shock, despite a great deal of time in the industry. Perhaps we should prevent people from buying transformers now, because they don't know how to use them safely! A piece of EU rubbish now prevents one from using many useful chemicals, as some bureaucrat has decided that they are dangerous, including weedkiller, which now largely don't work at all.
  • 0
    David,


    Another perspective, is that whilst BS 7671 provides the basic electrical safety standard (and it is in this respect that the other standards refer to BS 7671), the other standards fulfil the role of functional performance and application- or system-specific requirements. For BS 7671 to contain the performance requirements in the plethora of standards (e.g. BS 6701 alone can't be used for telecomms cabling, it in turn refers out to a host of other standards including BS EN 50773-series and BS EN 50174-series) would mean it becomes huge, unintelligible in many respects, far more costly, and would require more frequent updates.


    So, perhaps it's not that the same information is duplicated in other places. In fact, BS 6701 is interesting in this respect - it was reeled back in respect of "crossover requirements" over 20 years ago - before that, I guess the history of the public telephone network meant that BT wanted more control over wiring and equipment connected to their network.

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