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5kw pool heater - can it be used on ring main

Discussion in 'Electrics UK' started by beezo, 27 May 2012.

  1. beezo

    beezo

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    Hi guys,

    I had a 3kw pool heater (portable looking type) that had a plug installed on it, anyway Ive bought a new pool heater which is 5kw and its not come with a plug.

    I know this is because you cant run a 5kw appliance off a 13amp fuse otherwise it will blow

    im gathering the correct way to install this would be to put it on its own circuit but this seems a bit over the top as it not like its going to be used all the time. Just the occassional use

    anyway, could you recommend a way of connecting this up tempoarary, so i can use it as a nd when please

    i know this isnt the 'correct way' but a ring main circuit on a 32amp mcb will take 7.2kw. could i make sure nothing else is switched on, on the ring main and connect it via a plug, fuse removed or another connection type

    advice appreciated
     
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  3. riveralt

    riveralt

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    You will need to install the 5kw heater on its own, RCD, protected circuit - and comply with the Building Regulations with regards to notification.
    You will be required to have the appropriate sized cable and MCB protection as well.

    This information will already be in the manufacturers instructions so you should comply with them rather than looking for an interesting new way to electrocute yourself.

    Water, electricity and humans do not mix very well!!!
     
  4. ericmark

    ericmark

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    As already said to comply with regulations and law no you can't connect to a final ring circuit.

    I will guess most of us have at some time tried to get that little extra. But one of the failings of the final ring system is one can lose the ring and it can become two radials without anything failing to alert one something has gone wrong.

    Following the guide lines of no fixed appliance over 2kW on a final ring in the main when it does go wrong nothing untoward happens between the fault and next scheduled test.

    Items like a kettle just don't run for long enough for cables to overheat even when there is a fault.

    However items like the immersion heater can run for hours not minutes which will allow serious overheating. Something like a swimming pool could take days to heat up and clearly any fault would be likely to manifest itself as a serious fire.

    Even at 3kW it should not be powered from the final ring.

    OK if everything as A1 and there are no faults anywhere in the system you may get away with it. But in real terms it's unlikely everything is A1 if you were that type of guy who tested the system at the prescribed time periods then you would not even think about connecting to the final ring so likely there are faults and fire risk is quite high.
     
  5. Spark123

    Spark123

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    A ring final circuit is meant to have it's loading spread around it, not all drawn at a single point.
    It is not suitable for what you suggest, it needs to be on it's own radial circuit.
     
  6. ban-all-sheds

    ban-all-sheds

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    A temporary dedicated radial circuit capable of supporting the load.
    Re the final point - temporary circuits need notifying and Part P compliance in exactly the same way as permanent ones.


    Also, how far from the pool will you want to have the socket?
     
  7. stem

    stem

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    Removing the fuse would break the circuit, so I'm assuming that you are suggesting replacing the fuse with a solid link instead. Apart from what has been stated above the plug, and or, socket would probably melt anyway. They are called 13A plugs for a reason and will often get warm when used for a while with loads of 2kW or above.
     
  8. janner10

    janner10

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    Are you seriously asking if you can power from the ring with a plug and putting a nail or something instead of the fuse?

    If so, you're a bloody idiot.
     
  9. OwainDIYer

    OwainDIYer

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    It would be "slightly" safer than connecting two 13A plugs in parallel.

    STILL DANGEROUS THOUGH SO DON'T DO IT.
     
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  11. ban-all-sheds

    ban-all-sheds

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    Wrong.
     
  12. timbim

    timbim

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    A widowmaker has exposed live parts. Lack of a fuse doesn't, and in the case of a fault, the CU fuse may offer some protection. A widowmaker can kill you quite easily even with RCD protection.
     
  13. ban-all-sheds

    ban-all-sheds

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    So can crossing the road without looking, or deciding to hold a chef's knife by the wrong end.

    TBH I hadn't thought about the widowmaker aspect, but when we drive cars we are happy that we are paying enough attention to come within inches of sudden death all the time.

    The plug with a nail could kill you when something outwith your control goes wrong. The widowmaker could only kill you if you did something stupid with it.
     
  14. timbim

    timbim

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    I suppose from the aspect of coming across either a widowmaker or a lead with the fuse replaced with a solid link, there is another way to look at it. It could be said that the widowmaker can be written off as unsafe on the most cursory visual inspection, whereas from the outside, the shorted fuse may well look fine. If it had been used previously for any period, it may well give you a few clues though!

    I maintain, however, that exposed live parts is the most dangerous situation you can develop in this context.
     
  15. OwainDIYer

    OwainDIYer

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    please note I wrote lack of a fuse would be slightly safer than a widowmaker. [/b]
     
  16. ban-all-sheds

    ban-all-sheds

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    It really is 6 of one, half a dozen of the other. As you say when you see the widowmaker you either don't use it or use it with extreme caution, thus significantly lowering the risk to you. When you see the plug with a nail in it you have no idea it has risks.

    Or do you treat the widowmaker by-product of having two flexes and two plugs with caution? You might not realise what you were seeing - it's not the same as a flex with a plug on each end.

    I hadn't thought about the fact that if you had two supply cords you'd create a widowmaker, so I apologise for saying "wrong" - it's a valid opinion.

    I can't decide whether one is slightly worse than the other. There are things you can do to mitigate the widowmaker risk to make it much safer than the nail, but recognising that you had to should also tell you not to do it.
     
  17. big-all

    big-all

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    as an aside
    the physical plug and socket would fail with such a load in quite a short time just in case your tempted :oops:
     
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