NEMA 6-50R Plug Conversion

[PeterH]

18 minutes ago, neilestrick said:

Ideally, yes, but with the way the elements are wired in series that's not really possible. I wonder if they have a different element configuration on newer models that could be used.

Would a 208V 3-phase to 208V single phase conversion have any attractions? Need a big transformer of course.

[Bill Kielb]

1 hour ago, neilestrick said:

Ideally, yes, but with the way the elements are wired in series that's not really possible. I wonder if they have a different element configuration on newer models that could be used.

Thinking in terms of wattage, the center series group is likely close in wattage to top and bottom so maybe 2500 w which means 11 amps so both centers likely could go on a single relay. If not, add a relay and parallel feed the relay coils as zone 2. It’s very likely all possible Just  need to know the real values of everything to figure out the best way though.

[Bill Kielb]

1 hour ago, PeterH said:

Would a 208V 3-phase to 208V single phase conversion have any attractions? Need a big transformer of course.

I am not aware of anything simple. My thinking is  we really need to look at the present service, 240v single phase and decide is it easier to convert the kiln or do we really want to change 240v single phase to 208v three phase in a pure resistance environment. My strong hunch is convert it to 240v single phase operation 

[PeterH]

2 hours ago, Bill Kielb said:

I am not aware of anything simple.

Sorry, I don't seem to have made myself clear. I'm thinking of a power-side that consists of

-  3 x 208V elements
- a power relay for each
- the complexities/cost of a transformer.

Seems likely to be as least as simple in the boxes as Neil's 1st & 2nd options to fix the 250V safety issues, and would presumably allow per-zone control if required.

[Bill Kielb]

1 hour ago, PeterH said:

Sorry, I don't seem to have made myself clear. I'm thinking of a power-side that consists of

-  3 x 208V elements
- a power relay for each
- the complexities/cost of a transformer.

Not sure I follow. This kiln contains six elements, center section are series connected to form a pair or four elements total, top, bottom and two center.. Single phase to three phase conversion by transformer is very difficult . Again, lots of speculation though. Best thing I think, is to know everything about the kiln, operating voltage, intended wattage, resistance and start designing from there.