Plastic external consumer unit ? Is it allowed ?

Hi guys.   I probably need to install a consumer unit outside. Customer has purchased an induction hob. CU is the other side of the house, house is less than 10 years old so all chipboard floors etc and she doesn't want the disruption. The meter box is on the same wall as the kitchen hob and has an isolator in it ( i dread to think how the tails are run but that's a different story ) . Anyway there is no room in the meter box for a 2 way CU so she has asked for an external one can be fitted. It's on the side of the house behind a fence so not quite as bad as it sounds.    

In these days of metal consumer units is it compliant to fit a plastic enclosure, a wiska type of thing with a din rails in it etc or would it still have to be metal even though it's outside so nowhere for a fire to spread.  Any searches i am doing at the moment just bring up the plastic variety anyway. 

As a side i need to leave a spare way in it for a possible future car charger.

Thanks

Gary

  • Yes I would say that’s fine to fit a plastic one outside as it’s not “within” domestic premises, and assuming that it’s on a non-combustible surface and any fire wouldn’t spread into the house from where it’s located. Hager do a decent ip rated one.

    BG do a nice little 3-way IP rated metal consumer unit that is solidly made and can come with a main switch or rcd. They also do a version with surge protection if you need that. It gets a little more complicated with the ev charge point as their rcbo’s are only single pole. 

  • I'd be slightly wary of meddling fingers being attracted to a simple CU visible outside - maybe install a 2nd meter box and then put the CU inside that - which might give you a better range to choose from (and easier to maintain IP ratings for cable entry too). Can be surface fitted if that's easier - e.g. https://www.tlc-direct.co.uk/Products/MBEB6.html

       - Andy.

  • I am afraid that "premises" are not restricted to a house. The origin is a deed which conveys all the land which is transferred on a sale so it includes the house, the garage, any outbuildings, the gardens, etc.

    I like that BG cast CU - built like a brick dunny, but I would only install it under cover such as a porch, etc.

  • I think there is no problem with plastic cased switch-gear in situations where the fire risk is in effect mitigated by another measure .  In this case that it cannot possibly set fire to the building.  If the corrosion risk to a steel one is actually more serious, then I'd go further and say that plastic becomes preferable.

    The rule is "

    421.1.201  Within domestic (household) premises, consumer units and similar switchgear assemblies shall comply with BS EN 61439-3 and shall:

    (i) have their enclosure manufactured from non-combustible material, or

    (ii) be enclosed in a cabinet or enclosure constructed of non-combustible material and complying with Regulation 132.12.

    Notwithstanding the legal definition of premises to include the garden, the common use is to consider the the garden to be the 'outside' the intention of the regulation is clearly to avoid the spread of any  fire to the inside of buildings where folk may be hurt,

    Mike.