Power Line to my house was broken

[etpm]

The overhead 22kV line is 3 phase Delta, so with two transformers you get three phase out, but you only need two transformers. (One between A&B, one between B&C, which get you the three 240V Delta phases, two of which, A&B, are 120V to ground) It is called an open delta-open delta configuration. More here on slide #10.

You got it! The house has the two phases that are 240 to each other and 120 to ground. The three phase 240V runs the well to minimize power losses in getting the power to the submersed pump motor which is 600'+ from the pole.

All the best,

Peter

So you already had 3 phase, just at a higher voltage. The transformers are not making 3 phase. I have a similar situation in my machine shop. The voltage runs right at the high limit and sometimes goes over. I make my own 3 phase with a rotary phase converter but it does nothing about the high voltage. One of my machines cannot tolerate the over voltage so the spindle drive kept shutting down. I installed a pair of buck/boost xmfrs wired in buck configuration to reduce the voltage to just the one machine. It no longer shuts down.
Eric

 

[ponytug]

So you already had 3 phase, just at a higher voltage. The transformers are not making 3 phase. I have a similar situation in my machine shop. The voltage runs right at the high limit and sometimes goes over. I make my own 3 phase with a rotary phase converter but it does nothing about the high voltage. One of my machines cannot tolerate the over voltage so the spindle drive kept shutting down. I installed a pair of buck/boost xmfrs wired in buck configuration to reduce the voltage to just the one machine. It no longer shuts down.
Eric

Yes my power company had three phase to begin with. Not every area around here is wired for three phase on the poles. I do not know why the original owner did it this way.

I use a VFD for my old three phase machine tools in the shop; there is only normal 120/240 there. I did do some extra add ins with some additional ferrite loops to limit harmonics in the old motors. I am glad that the rotary phase converter and buck transformer work for you.

All the best,

Peter

 

[etpm]

I have been using the same phase converter for about 20 years. It is very well balanced. Runs my CNC machines just fine. It will start 15 HP and run 60, but the most I've ever had running at one time was about 40 HP.
Eric

 

[ultrarunner]

Since 1985 I use rotary convertors.

One for Bridgeport NC machine and one for old Develbis compressor.

Never got sophisticated and need to manually spin convertor to start.