Wye or Delta

[coulter]

You're right. Sloppy me for assuming 480V. After I reread, I realized that because the original post was talking about Delta or Y, that I assumed 480V. 208 would never be Delta and would always have a neutral, and 240 wiould never be Y. But, as you pointed out, nobody ever said that.

carl

 

[brian john]

For the record

The distribution is 480/277 VAC 60 HZ 4-wire wye to three ATS's, one ATS for Lighting loads, 3-phase 4-wire, there are two ATS's with the 3-wire load connections UPS and Mechanical.

 

[drbond24]

That just means that the UPS and mechanical equipment are three phase loads. No single phase loads, no neutral needed, no problem.

 

[coulter]

Brian -
Amazingly I guessed correctly. It really wasn't much of a guess. I was pretty sure you would have said something if the system was other than normal. My post stands.

carl

 

[brian john]

DR I am not sure if you are following along read my OP.

That just means that the UPS and mechanical equipment are three phase loads. No single phase loads, no neutral needed, no problem

I KNOW THIS my question was PROPER TERMINOLOGY.

 

[drbond24]

While the utilization equipment may be Delta connected is the distribution properly designated Delta?

The answer to that question is no. It is 3 wire wye. Not sure what else you might mean.

I was just agreeing with coulter:

Pretty common in industry. No single phase loads, so no need for a neutral. Of course, none of this is news.

The plant I work in is this way. Distribution is 3 wire wye. Don't need a 4th wire since everything is 3 phase.

 

[drbond24]

I just called Square D's technical support number and was told that there is no problem at all with connecting 3 wire wye to a delta primary transformer. I stand corrected.

 

[brian john]

I hope not I have been doing it for 37 years

 

[drbond24]

It's something I've been around constantly but never really thought about until this thread came up. Obviously it works; it is everywhere, even in the building I'm sitting in right now. I just need to pay more attention.