Hotel External Lighting - RCD

Good afternoon

We have some bollards and lighting columns at the backyard of a hotel

We are feeding them with XLPE/SWA/LSF cables through ducts.

Do we need RCD protection at the board?

I am looking into BS7671 section 714 - OUTDOOR LIGHTING INSTALLATION and there doesnt seem to be anything to indicate an RCD apart from a telephone kiosk, bus shelter, advertising panels and town plans.

Do I read it correct or having a steel column makes a difference and I do need an RCD?

I wouldnt normally ask however I remember in the past people in here pointing out that the external lights need RCD and refer to some BS7671 clause but my memory isnt that good

Thanks

  • Something like the below

    714.411.3.4 Additional protection
    Lighting that is accessible to the public shall have additional protection by an RCD having the characteristics specified in Regulation 415.1.1
    Examples include:
    1. Gardens, spaces open to the public
    2. Telephone kiosks
    3. Bus shelters
    4. Advertising panels and town plans
    This list is not exhaustive.
    The following are excluded:
    5. Street lighting and traffic signage
    6. Illumination of monuments
    7. Platform lighting at rail/bus stations.

    In view of the above quoted regulation, it could be argued that RCD protection is needed for certain types of car park lighting, especially bollards, which are easily damaged by cars and vandalism

    IIRC it was 18th edition BS7671 amendment 2 after child got electrocuted in the pub beer garden 

  • Appropriate Regulation referenced above by  

    Some more background as to why you ought to provide the RCD, regardless of what BS 7671 says, is provided in the information and advice from the HSE here: press.hse.gov.uk/.../

    Further to all of that, BS 7671 is a minimum standard - there are particular use-cases for spaces open to the public, major infrastructure, workplaces, etc., where additional measures may be required depending on risk assessment (including CDM risk assessment, as pretty much all electrical installation work, including maintenance, is classified as construction work in CDM).

  • mind you that pub had so much wrong with it that an accident was waiting to happen - the wiring to the outside lights was utterly negligent, but so were many other aspects it was quite a catalogue.

    An RCD may well have saved the youngster, if he was well grounded, but I'd not like to suggest that an RCD magically makes that sort of installation standard OK in the UK.

    The alternate view for  your lights question is how dangerous does it become if the RCD trips due to a none- fault event and is not reset fairly smartly afterwards ?

    I'd consider a few bollards (as it sounds like) going off and staying off all night, not to be an issue, so long as there is other lighting, but if it also plunges into darkness, say the only illumination for a narrow set of uneven stone steps or something, there is also a counter safety case for keeping at least some of the lights on - as there is for streetlights on main roads. This may not apply here however but is a more general comment.

    Mike

  • Thanks

    Number 1 was not in BS7679 Amendment 1

    I just checked and it is now in amendment 2

    So this looks to be a recent thing. Am I right?

    Basically as I understand the principle behind this....ANY metal furniture/electrical item outside that can come in contact with public should be under RCD.

    For example I have a PTZ Camera on metal pole that needs power supply.

    I am thinking it should be on RCD as well under the same principle.

    At least that's how I see it after this list of items you have posted

  • A further thought to this scenario could be a 240v supply via RCD to the center of the carpark to a pillar/column/cabinet and then 36v or 48v to the lights.  This would allow for each light to be on its own radial circuit for testing/maintenance and isolation.  The cabinet/pillar could have some extra protection like perimeter barriers 50cm to 100cm beyond the cabinet as it a car park.  Cable length and volt drop would need to be calculated if 36v/48v is used as there are limits on the length. 

  • Would other metal electrical structures that can be accessed by public be in this RCD category too?

    For example a metal motorised sliding gate or a camera pole with 230V to the camera etc

    I mean, if we consider a lighting post or o bollard a danger to public why would it be different for other 230V metal structures?

    Just wondering 

  • In terms of the chance of a shock risk, it probably isn't much different - a light or a camera or a motor screwed to an metal fence is very similar. There is a general question of different sorts of risk to be balanced - is it better if the power goes off or not? Public street lights are not RCD because the aggro of them not being reset if there is a (very unlikely) trip is considered more dangerous than the (also very unlikely ) double fault needed to reach a dangerous condition - namely a CPC failure and then an insulation fault. Thirdly, lamp posts are painted - which is not formal insulation per-se but is likely to limit shock current, and then they are not held onto intimately by folk with wet hands and feet.  A camera pole is similar, but a gate mechanism may be more likely to be touched (postman or a side-gate for pedestrians) and or there may be situations where the power going off is more dangerous than it staying on - if for example folk are then locked in.

    The list is not meant to be the last word - more that 'here are the sort of things to think about' In that sense it makes it hard to be sure if the requirements of the regs have been met as intended or not, and there needs to be a clear policy from the security side with things like doors that lock and so on as to what happens in a power cut. It may be that cameras and locks running from 12 or 24 v are preferred in some situations - both eliminating the shock risk, and allowing a 'diode-or' with a back up battery.

    That's not much help to you in terms of not being black and white - but as so often, it needs the whole system design 'in the round' as it were, and a clear design authority who can balance these decisions.

    Mike.

  • Would other metal electrical structures that can be accessed by public be in this RCD category too?

    Let's have a look at BS 7671, taking into account Section 714, but ignoring other Special Locations for the purposes of discussion.

    In this thread so far, we appear to have been discussing 714.411.3.4, which modifies Regulation 411.3.4 for parts of an installation within the scope of Section 714. The application of Section 714 is discussion in Regulation 714.1:

    714.1 Scope
    This section applies to outdoor lighting installations comprising one or more luminaires, a wiring system and accessories, and to highway power supplies and street furniture.

    The following are included in outdoor lighting installations:

    (i) Lighting installations such as those for roads, parks, car parks, gardens, places open to the public, sporting areas, illumination of monuments and floodlighting
    (ii) Other lighting arrangements in places such as telephone kiosks, bus shelters, advertising panels and town plans
    (iii) Road signs.

    The following are excluded:

    (iv) Temporary festoon lighting
    (v) Luminaires fixed to the outside of a building and supplied directly from the internal wiring of that building
    (vi) Road traffic signal systems.

    So, 714.411.3.4 applies to anything discussed in 714.1, except the list of excluded items in 711.411.3.4 (v) to (vii).

    Security systems such as CCTV are NOT listed as part of the scope of 714.1.  However, there is nothing to prevent a designer from taking the view that   puts forward, that the risks are little different if it's a metal pole with mains in it (and these days, could be similar power if mains).

    However, Section 411 also has requirements for things that require RCD, in 411.3.3 and 411.3.4. 411.3.4 applies to domestic (household) premises only, and requires lighting in those premises to have RCD protection. Let's assume these premises are not household premises, so we can ignore that. This then leaves 411.3.3, which requires socket-outlets rated up to 32 A, and mobile equipment rated up to 32 A for use outdoors, to be protected by RCD.

    So, there is no BS 7671 requirement for a general (non-lighting) piece of equipment (such as a heat pump) that is connected via direct wiring or a connection unit, to be protected by RCD. However:

    I think we need to remember, that whilst we have an industry standard that is a "minimum", as designers we have a legal duty to work with the Client (or if it's a domestic Client, and the electrical contractor is the only contractor, we take on the duty of the Client) to ensure an installation that is safe to use and maintain, which can sometimes provide additional requirements over and above BS 7671.

    "I didn't fit an RCD because BS 7671 didn't require one" might not be a good enough argument if a risk assessment ought to have been done that indicated residual risk that could have been mitigated by the use of an RCD.

  • Basically as I understand the principle behind this....ANY metal furniture/electrical item outside that can come in contact with public should be under RCD.

    That could be read as including steel street lighting columns, roadside communication cabinets, outdoor units of air conditioning systems, even outside taps bonded to the MET via metallic pipework - which might be a bit OTT.

       - Andy.

  • Hi Andy

    Have a look at my original reply

    The following are excluded:
    5. Street lighting and traffic signage
    6. Illumination of monuments
    7. Platform lighting at rail/bus stations.