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Quick question on Loads, Currents & Cabling

Discussion in 'Electrics UK' started by c0wb0y, 9 Oct 2017.

  1. c0wb0y

    c0wb0y

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    Hi folks,

    As an electronics guy, I mostly operate in the 5V and 12V realm but wanted to run the following question on loads and wiring ahead of our test equipment arriving next month:

    We'll have 16 x test machines running 24/7 with each consuming max 850W off a standard 13A UK plug/kettle lead (that's 13.6kW or ~60A @ 230V).

    Whilst there are many ways of doing this no doubt (and we have 3 phase too), cost is a concern. I like the idea of having dedicated circuits for these sort of things so would the following suffice:
    1. Fit 2 x 32A new breakers/RCBOs to create 2 new Ring Mains each with 4 x double sockets (16 sockets in total)? That would allow us to have 8 machines per ring main. According to my calcs, the above would give a 2A contingency per new circuit (<7% of load) but remember, 850W is the max consumption with the average being closer to 800W and the units themselves as well as the power supplies are all fused.

    2. Should this be done in 2.5mm or 4mm T+E given the max distance from fuse board to last socket on either circuit will be <6m?

    3. Off topic but do sub-meters sync accurately with main meters? If so, are there any cheap-ish recommendations so we can gauge the total units consumed (I assume we'd need 2 if the above setup works)?

    The rest of the premises uses very little to no power (a few laptops and 3 tube lights - no other heavy loads). If the above works, it sounds simple (and cheap) for a sparky as everything is ready, open and easily accessible.
     
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  3. aptsys

    aptsys

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    What's a kettle lead?
     
  4. c0wb0y

    c0wb0y

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    The IEC 60320 plug - the type that fits to kettles/PCs etc. etc.
     
  5. aptsys

    aptsys

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    They're not interchangeable. Kettles traditionally use C15 plugs, whereas PCs etc are C13.
     
  6. EFLImpudence

    EFLImpudence

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    Use 4mm² then you don't need a ring.
     
  7. c0wb0y

    c0wb0y

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    Aaaa - you mean like a Series lighting circuit? This makes sense for us PCB workers!
     
  8. EFLImpudence

    EFLImpudence

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    Not really, that would be parallel.

    I just mean there is no point having a ring.
     
  9. c0wb0y

    c0wb0y

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    Any other thoughts on this apart from using 4mm straight through and not having a ring?
     
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  11. chappers

    chappers

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    they are one way, could use the kettle lead to power the PC but not the other way round
     
  12. c0wb0y

    c0wb0y

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    how about question (3) anybody?
     
  13. ban-all-sheds

    ban-all-sheds

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    Yes.

    This is a place of work, and you are not qualified to design its electrical installation.

    You must discuss your requirements and preferences with the electrician who will be doing the work.
     
  14. ban-all-sheds

    ban-all-sheds

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    They are in one direction.
     
  15. c0wb0y

    c0wb0y

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    Was waiting for a 'call an electrician' smarty pants to step in - there's no harm in acquiring knowledge beforehand so I know what the cheapest option is. FYI: I did call one who kept banging on about tapping into a new phase and opening a new line altogether - sounded very $$$ to me.
     
  16. winston1

    winston1

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    I think you'll find it is £££ in this country.
     
  17. winston1

    winston1

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    They don't sync with the main meter, but there is no reason for them not to be accurate.
     
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