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Converting 3 phase to single phase

Discussion in 'Electrics UK' started by Talay, 10 Jul 2019.

  1. Talay

    Talay

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    I have a building which has and needs 3 phase power but I also have some machinery which I want to use that is single phase.

    So on a circuit that is currently 3 phase, what has to be done to turn it into single phase ?
     
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  3. conny

    conny

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    You need a neutral and a qualified spark.

    In fact it's unusual not to have at least one single phase circuit.
     
  4. JohnW2

    JohnW2

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    As has been said, you need an electrician - but, just to explain, one does not 'convert' 3-phase to single phase but, rather, one just ones one (or more) of the three phases (plus a neutral) as a single-phase supply. As has also been said, it's a very common situation, so any electrician should be familiar with it.

    Kind Regards, John
     
  5. wgt52

    wgt52

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    Get an industrial electrician in to do the work. I presume the premises already have electrical socket outlets. It's possible to have different 'phases' in ajacent sockets which can be dangerous if not known about. A good electrician will know how to resolve it and warn about it.
     
  6. DetlefSchmitz

    DetlefSchmitz

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    People often say this . I have often wondered why...
     
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  7. JohnW2

    JohnW2

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    Same here, in most senses - just like the excitement when two or more phases are present in the same enclosure - even though 230V PDs are plenty high enough to kill!

    In the current context, the one thing I would say is that if two 'adjacent' sockets are on different phases, they will inevitably be on different final circuits - so, as in any situation in which there were 'adjacent'/nearby sockets on different final circuits (whether the same or different phases), I'd perhaps be inclined to have some 'warning notices', pointing out that more than one circuit had to be isolated in order to kill all the sockets.

    Kind Regards, John
     
  8. DetlefSchmitz

    DetlefSchmitz

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    Different circuits I sort of get. Though it is always said that if you don't check for dead then you are to blame for the consequences.

    Different phases just means that if you decided to connect something between live on two different sockets and expected the potential difference to be zero, you would get a surprise. Seems like a non-issue to me.
     
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  9. JohnW2

    JohnW2

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    Agreed - but whilst one obviously should not have to design on the basis of future stupidity, nearby sockets on different circuits are perhaps a 'tempting target' for such stupidity, and hence perhaps worth doing some 'warning' about.
    Quite so.

    I may be wrong (don't have my copy to hand), but I have a feeling that BS7671 dropped the requirement for a warning label about 'different phases in an enclosure', didn't it?

    Kind Regards, John
     
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  11. sparkwright

    sparkwright

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    I wouldn't mind Flameport doing one of his videos showing what happens when inserting something between two phases.

    With him kept safely away of course...
     
  12. sparkwright

    sparkwright

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    Assuming you have a 3 phase and neutral supply, and a 3 phase distribution board, single phase circuits can be created easily with single pole circuit breakers.

    This is work for electricians and not DIY work.
     
  13. ban-all-sheds

    ban-all-sheds

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    There are DIYers here who would be quite capable of doing it.

    But the OP isn't one.
     
  14. sparkwright

    sparkwright

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  15. JohnW2

    JohnW2

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    ... as 'entertainment', perhaps - but it's very hard to see how any such event is going to occur in practice (either accidentally or as the result of some deliberate action).

    A "video showing what happens when inserting something between L and N of one phase" might well be just as 'entertaining'!

    Kind Regards, John
     
  16. SUNRAY

    SUNRAY

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    depending on the size of the OCD there may be very little difference.
     
  17. JohnW2

    JohnW2

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    Exactly my point.

    As I've said, whether in terms of 'flashes and bangs' or the ability to kill, 230V pds are not necessarily going to be appreciably different from 400V - so, like Detlef, I'm not sure I really understand the excitement there often is about two phases being 'nearby' or 'in the same enclosure'.

    Kind Regards, John
     
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