CU Position

Midwest · Jun 10, 2012

Hopefully will re qualify next year. Colleagues & friends are already thinking of using me to do some work for them then, which is good! I've had my nose buried in the various books, however I'm getting confused over the positioning of replacement CU's.

A friend wants his CU replaced, but it is currently in a cupboard above his kitchen wall units.

Building regs Part P, states the CU (or other switches) should be installed above the flood plain, not installed where young children may interfere with them, but recommends installed above 450mm - below 1200mm, for accessibility by disabled persons (M document). RCD/RCBO's should be readily accessible.

However, it goes on to say M doc' applies to new builds and there is no requirement in rewires, providing it is left in no worse terms of level of compliance.

Am I right in thinking that my fiends CU can stay where it currently is? If it can’t, then circuits/tails would need extending, which would be a common issue for most CU's
My neighbour has had a CU changed. The original was in a cupboard next to the kitchen. The cupboard was knocked through into the new kitchen, and the CU moved up the wall next to the ceiling (i.e. above 1200mm),so that goes against M doc’ recommendations?
Is there reference to this in BS7671?

micknew · Jun 10, 2012

It can stay where it is.

micknew · Jun 10, 2012

New heights apply to new builds.

telectrix · Jun 10, 2012

installed above

450mm - below 1200mm

, for accessibility by disabled persons (M document)

that bit's for sockets and switches. Cu recommended height is 1200 - 1500 mm ( i think) but you are correct in that that is a recommendation for new build. in your situation, you fit wherever the client wants it. obviously, as you are connecting existing wiring, it's logical to fit CU in same placxe, thus avoiding having to join cables.

Des 56 · Jun 10, 2012

When you carry out rewiring,the heights recommended in the building regs needn't be followed
You can put them at existing or lower,what you should avoid, is making the contravention any worse,eg raising switches that are already too high

Consumer units and their location is a debatable subject
What is recomended for their location is arguable and can be a contradiction (the building regs make statements that can be twisted to suit the opinion of the installer or building inspector at that time)

My own installs and the issue of building regs is generally covered by telling the client what they are supposed to follow, then putting things exactly where "they" and common sense would have them sited,then leave that building reg book to the die hard conformists :smilewinkgrin:

Midwest · Jun 10, 2012

Thanks chaps, I see that common sense prevails. On slightly pedantic note, if my last example was in a new kitchen extension, would that not have to comply as a new build? If you had a really picky Building Inspector?
450mm – 1200mm for CU’s seem to remember that featuring in a‘learning lounge’ video with Steve Austin.