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522.6.203 RCD protection required for cables in metal stud walls, what about ceilings?

Sparkingchip
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    Okay, that’s what it says in BS7671 The Wiring Regulations.


    This is what it says in NAPIT Codebreakers:

    caf3c77ea88aadbc9da427dd9558e333-original-2150b4be-75d4-4f84-98c0-4b19779df26d.jpg
  • 0
    I suppose I had better ask my question.


    In the last week I have completed two landlords EICRs in flats, the outer walls are brick and block, the inner partition walls are timber stud, the floors between stories are concrete with plaster board ceilings suspended on steel ceiling joists.


    So the internal walls are timber, but the ceiling has a metal frame with the twin and earth lighting circuit and other cables lay across the metal work and across the back of the plaster board, as I discovered by removing a down light fitting to inspect above the ceiling.


    Neither flat had RCD protection to the lighting circuits when I arrived, but they did when I left.


    So how would you code the lighting circuits without RCD protection in a flat with cables concealed behind plaster board dabbed onto block work, in timber stud walls, lay across a metal framed ceiling, also supplying the bathroom light and extractor fan?


    Andy Betteridge
  • 0
    Maybe a distinction made between cables in a metal partition and cables on a metal partition. Personally I wouldn’t give a stuff what NAPIT say in their code breakers. You are the inspector so you make the call.
  • 0
    Inspecting above the false ceilings in new build flat built since the 1990’s with metal framed ceilings is revealing really shoddy electrical installation work carried out by electricians.
    • Down lights and smoke alarms with the outer sheath of the twin and earth cable stripped back by up to 200 mm and the cable retaining clamps not used.

    • Three MCBs in a consumer unit two marked lighting and one smoke alarm, but the smoke alarm is supplied from one of the lighting circuits, leaving the MCB connected to a cable that apparently does not have anything on the other end of it and may be just a cut cable lying on top of the metal framed ceiling.

    • Cables passing though holes chewed through the sides of the metal joists to allow light fittings and smoke alarms to be secured through the plaster board to the metal work above.


    Really the ceiling is a metal framed partition laid flat, I was wondering what the real intent of 552.6.203 is, does its wording include or exclude ceilings?


    The opportunity to inspect above the ceiling is limited, usually it is only possible where there are down lights that can be dropped down, but as they were one of the “must haves” in flats built at this time the usually is an opportunity to have a look.


    I am having to take a light switch off and take the back box out to confirm what the studs are made of in partition walls. I carry a camera with me and take a considerable number of date stamped photos during the inspections and like to get a photo of the switch I have taken apart and a stud in the wall.


    The last EICR I did was a sixteen year old new build flat with a metal framed ceiling over timber stud walls and two way switching had been installed for the bedroom lights without a CPC leaving the galvanised back boxes without an earth connection, as it was wired in insulated singles without a CPC, so I am not talking about jobs that were completed to an acceptable standard in the first place, despite having been completed by major electrical contracting firms.


    Andy Betteridge
  • 0
    "Personally I wouldn’t give a stuff what NAPIT say in their code breakers. You are the inspector so you make the call. " 


    So, who are we going to call?  ?



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  • 0
    IIRC, this regulation was down to an incident where careless fixing of plasterboard and skipping testing caused permanent contact between a live cable and a metal partition frame in a bathroom. Later the boiler leaked causing a puddle on the floor that reached under the plasterboard to the metal frame. Tenant knelt in puddle while trying to close a nearby stopcock, and died.
  • 0
    The one flat I moved the lighting to the RCD protected side of the consumer unit, in the other I swapped the main switch out for a RCD, a quick fix in both flats.


    So both flats now have all their circuits protected by a RCD removing several  observations and codes from the EICR.


    I won’t be able to do something like that every time, so some will have to be coded.


    Make a determination.


    Andy Betteridge
  • 0
    Sparkingchip:

    The one flat I moved the lighting to the RCD protected side of the consumer unit, in the other I swapped the main switch out for a RCD, a quick fix in both flats.


    So both flats now have all their circuits protected by a RCD removing several  observations and codes from the EICR.


    I won’t be able to do something like that every time, so some will have to be coded.


    Make a determination.


    Andy Betteridge  




    ​​​​​Trying to balance risk of danger from livened up metal parts and risk of danger and inconvenience from all ccts on one RCD: perhaps not an easy choice to make while also factoring in cost.


  • 0
    Millions of people live in homes with a single upfront 30 mA RCD as the main switch, it’s not a big issue.


    Andy B
  • 0
    Sparkingchip:

    Millions of people live in homes with a single upfront 30 mA RCD as the main switch, it’s not a big issue.


    Andy B


    So why does GN1 say it shouldn't normally be done?


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