single phase to 3-phase

[c.c]

was wondering what size of transformer i waould need to go from single phase to get 100amps 3-phase

 

[iwire]

Without knowing the voltage there is no way to determine the size.

But no single transformer can make 3 phase from single phase, at least as far as I know.

 

[Minnesotaelectric]

What type of load is it? If it is a motor load, maybe consider using a vfd.

 

[drbond24]

was wondering what size of transformer i waould need to go from single phase to get 100amps 3-phase

Transformers don't turn 1 phase into 3, they just change voltages (and therefore currents).

The only thing I know of off the top of my head that can do that is a VFD like Minnesotaelectric mentioned.

 

[mivey]

3 phase kVA = amps * sqrt(3) * V_line-to-line / 1000

3 phase kVA = 100 * sqrt(3) * V_l-l / 1000 = 0.1732 * V_l-l

But, as iwire pointed out, they don't make a single transformer that does that. You would think somebody might come up with a a 120/208 version, but I don't recall seeing one.

The problem with single phase to three phase, is that you need at least two voltages that do not lie along the same axis. Most single-phase is from a center-tapped transformer, and the neutral point lies along the vector of the line-line voltage.

The 120/208 has a neutral point that does not lie on the vector of the line-line voltage and is a candidate for deriving three phase. I don't know that anybody actually does it.

 

[mistabass]

hi all new to site just wanted to say hi i have used a phase convertor had single phase service and 3phase mahines worked out great the one i used was 60 amp do think they make bigger ones

 

[Rockyd]

Welcome to The Forum.

You could possibly use the old formula of 58% inverted.

You would have to have two hots for phase differential and would do well to talk to a rewind shop, or VFD manufacturer for whatever purpose you have in mind for this application.