DIYbanter - View Single Post - 3-phase vs single-phase heating elements

John

wrote:
Figured you guys would know...

I have found a used 220 v 3-phase oven that I would like to use in my
shop. The problem is that I only have 220v single phase. Without
going to a phase converter is there a way I can run the oven off of
single-phase by re-wiring the heating elements? IOW...how would I
reconnect to single phase to not overload the elements but also give
me the heat I need?

(Oh, even though I'm fairly electrical-challenged I did some homework
and learned that there are two basic ways 3-phase elements are wired,
star and delta. I just don't have enough knowledge of AC circuits to
figure out how to swap the elements or if it's even feasible.)

The first thing to do is determine if the elements are wired in Delta or
Wye (Star). Either way it will not be too hard to convert. You also
need to find out what control is on the oven. It the elements are in a
Delta setup you will have to rewire the elements so each element is in
parallel with the other. If the elements are in a Wye configuration you
will need a neutral wire to attach to the centertap of the Wye and tie
two of the high legs together and feed 220 across the single high leg
and the other set of two legs that are tied together. You could put
separate circuit breakers on each leg. One thing is that the neutral
conductor has to carry the current of two elements as should be sized
accordingly. Do not put a breaker or disconnect switch in the neutral
wire circuit.

None of the above will work with proprotional control circuits,
semiductor switching power control.

John