3Ǿ Transformer

My "transformer for dummies" book says the transformer will work but over time it will result in premature failure due to overheating from poor core saturation
 
Not a dumb question, and maybe not as simple as it would first seem. I was tempted to say sure, no problem.

But assuming it's a delta to wye, there is probably no connection to the 3 delta point.

1st winding will see normal L-L voltage, but then the other two windings will be in series across the L-L voltage. So their voltage should be too low, and maybe only half of what they should be.

Then we have to think about the coils of wire, and the magnetic flux, and what voltages that produces on the secondary windings, and maybe even how that reflects back to the primary windings.

So offhand, it doesn't sound like a good idea, and I could understand why it might die early (if it works at all).

Now if it was a Y to Y, I don't think it would be a problem.
 
steve66 said:
Not a dumb question, and maybe not as simple as it would first seem. I was tempted to say sure, no problem.

But assuming it's a delta to wye, there is probably no connection to the 3 delta point.

1st winding will see normal L-L voltage, but then the other two windings will be in series across the L-L voltage. So their voltage should be too low, and maybe only half of what they should be.

Then we have to think about the coils of wire, and the magnetic flux, and what voltages that produces on the secondary windings, and maybe even how that reflects back to the primary windings.

So offhand, it doesn't sound like a good idea, and I could understand why it might die early (if it works at all).

Now if it was a Y to Y, I don't think it would be a problem.
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To expand on Steve66... Technically, a winding of a 480 to 208/120 Delta to Wye transformer has 4 to 1 winding ratio. so each coil steps 480 to 120 and the connection points on the secondary would have to be from say A to B on the primary, but A or B to neutral on the secondary.
 
I have done it before for temporary power, using 480 single phase input. Substantially less kva though. Can’t remember if I had to change any of the taps, or just used H1 and H2 as input, but it was a delta wye. Delta delta would probably give you 240, 120 if if there is a center tap on one of the coils. But yours doesn’t have a center tap.
Little Bill said:
It is a delta-delta transformer.
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Most three phase transformers are nothing more than 3 single phase transformers sharing a common core. Your 45kVA unit could handle roughly 15kVA using a single winding. The nameplate limit is 54A on the primary.
 
jim dungar said:
No.
You use only 1 winding set like H1-H2 in and X1-X2 out.
Any other connection would require an analysis of the magnetic circuit and is typically discouraged.
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Then I don't think this transformer will work. I don't know the actual load, but it is fused at 100A.
This is for the oven mentioned in my thread about rotary phase converters. Someone mentioned running the oven on single phase, changing the elements, and using a transformer to boost the voltage.
 
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