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Struggling with insulated consumer units and information on power dissipation

Alan B

I am quoting for a new consumer unit to go in to  a domestic garage. Supplies 3 circuits in the garage and a couple of circuits to other outbuildings.

Especially with the recent guidance on metallic consumer units outside I have been leaning towards using a plastic consumer unit, then comes the challenge.

I don't think anyone still builds populated consumer units for more than 4 ways. So then I look at building my own and power dissipation, very little information available from what I can see, the only company providing data is MCG at 1a very low 11W.

The best I can find is that some enclosures state then are ok for say 63A, no idea what the assumed heat dissipation is. Also heat a dead end when looking for heat dissipation from RCBO's, I remember in the past seeing 12 to 15w at full load. So I seam to be left with a choice of putting a metal board in and hope it doesn't suffer from condensation, or puta plastic one in and hope it doesn't over heat. I could also put a metal board in a plastic enclosure, a bit less risk with heat.

I could probably just use any plastic din rail enclosure and not have an issues, but frustrating this is so difficult.

Thoughts?

Parents Reply
  • 0 in reply to Chris Pearson
    Chris Pearson said:
    If the garage is so damp that a steel-enclosed DB would rust away, it will not do much for the cars.

    Yes ... and no ... it depends on how long you want to keep the cars, but also on whether there's anything else going on (such as salt spray in the atmosphere) that might affect the corrosion of the CU vs the vehicle (latter may be better protected against salt corrosion than damp).

Children
  • 0 in reply to gkenyon
    gkenyon said:
    CU vs the vehicle (latter may be better protected against salt corrosion than damp)

    I find it extraordinary that cars made in the past 15 years or so do not rust.

    mapj1 said:
    a car gets driven about and maybe replaced after a few years, a CU less so

    Strange that people seem to want something as cheap as a CU to last longer than a car!

    How long do people expect a washing machine, for example, to last?

  • 0 in reply to Chris Pearson

    it is fixed infrastructure. I'd like the wiring and accessories to last the life of the building, much like the bricks and roof tiles which are also cheap, a brick is cheaper than a CU (!)  if it's that sort of garage and not some temporary wooden thing.
    I see no reason why PVC or PE wires going in now that are lightly loaded and out of the sunshine, should not be still in service in a century or two. A washing machine is not infrastructure, and has parts that perish or fatigue over time and so has finite life, looking at our own washing machine history, typically ten to twenty years perhaps.  Cars seem to fail due to something being beyond economic repair, suspension, dual mass flywheels etc. or collision damage.  Corrosion in a big way was more of a 20th century thing  - I presume modern paints are better, and maybe modern steels too.

    Mike.

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