Can a 240/120V three phase panel be used to hook up single phase circuits?

Question

I'm looking to install a three phase panel right behind my rotary phase converter that will be producing 240V delta. If I use a three phase panel rated for 240/120V three phase, is it possible to get balanced, single phase from the panel?

Answer 1

In general, "No".

Most rotary phase converters operate on single phase 240 V and manufacturer the third phase needed to operate 3Ø motors. All single phase load should be connected ahead of the phase converter -- preferably on a separate circuit from the main panel.

On a 120/340 V 3Ø 4-wire service, all 1Ø load (120 V or 240 V) is connected across the lighter transformer. Attempting to connect the 1Ø load on the manufactured phase is going to cause problems. Phase converters need to be balanced for the 3Ø motor load that is connected to them.

Answer 2

By definition, it will not be balanced. Also, it will be hard to do with a standard Delta output. If you have not bought the transformer yet, look at getting one that has a "high leg". This type has an additional tap that will give 120 Vac referenced to the incomming neutral (there normally is not a neutral in a delta transformer). This leg will carry more current, but a transformer designed to do this will specify how much current is allowed (30 amps per phase on the 240 and 10 amps on the single phase is pretty standard).

Answer 3

You can get 120V. output, but you've got to be careful.
Your 240V. Delta can be an solated system, so that by
center tapping one Phase to ground, you can take off
120V. to ground from two of your three legs.
This means that you must allow the rest of the 240V.
system to 'float`. (Some converter systems will ground one leg.)

You cannot get a balanced single phase 'Y` system
without a center-tapped transformer.

Answer 4

Yes.

On any three phase you get higher voltage between two of the 3 lines (legs), and between any line and ground you get lower voltage.

But get an experience person to do this for you. It is tricky, and legs need to be balance and Power factors should be watched carefully. Polarity management is an another issue to watch out can kill a person or set the place on fire.

Answer 5

it willl never be balanced out but they all 3 put out 75 Hz but can always go back words on a pannel example 3 faze to single faze but you cant go the other wayfrom single faze box to 3 faze without replasing the entire pannel

Answer 6

It might require some delta wye circuitry, but yes, it's possible.