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I have a oven with 9 elements of 660 watts each element. Therefore total wattage just under 6KW. It is wired 3 phase. I do not have a 3 phase supply. Can I wire three elements together i.e. 1980 Watts X 3 and feed them each with a separate domestic 13 amp ring main?

  • What's the voltage rating on the heating elements? What supply voltage do you have access to? – winny Oct 15 '17 at 10:33
  • The domestic supply I have can only be 220-240v I am unsure how to find out the voltage of the elements there is no markings on them. Thanks for the repy – Chris Gregory Oct 15 '17 at 10:38
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    If the elements will produce their rated power from 230V single phase, (and you CANNOT simply assume that!) connect them in parallel from a dedicated 30A (7kw) spur such as would be used for a shower. I'm assuming you're in the UK from your mention of 13A. – Brian Drummond Oct 15 '17 at 10:39
  • Does the oven have a label stating if it can be used on a single phase supply - if it does there may be another, inside, that shows how the connections can be changed to suit... – Solar Mike Oct 15 '17 at 10:47
  • Thank you Brian but I don't have that option available to me as a street trader I can't draw 6KW but thank you for the advice. – Chris Gregory Oct 15 '17 at 10:53
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Wired for Europe it is probably wired for 3-phase "wye" (like a Y). Each leg of the Y has a triplet of heating elements, with all of them tied together "in the middle" at neutral. The neutral may not be properly wired back to the neutral wire.

Where they all join in the middle for neutral, that would have to be eliminated. Each triplet must return its neutral to the same branch it gets its hot from, and the neutrals cannot mix. You could keep the triplet of elements together though. So each triplet would need to be isolated from the other neutrals.

It could be run on less than 3 circuits, but would not get as hot / would take longer to reach operating temperature.

A commercial machine would be built for this kind of reconfiguration; it is common.

Your bigger problem is the lack of certification-agency listing on the machine. If there's an accident, your insurance company may not pay out, and the authorities could hold you liable.

  • Thank you Harper that all sounds good advice. I assume what I proposed is possible. I just have to keep the three power feeds entirely separate. The existing heating elements are 84.8 Ohms indicated on my multi meter whilst the dial was set at 200 Ohms calibration. I assume I can use these original heating elements? – user76636 Oct 15 '17 at 13:26

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