transformer "?"

[sparkyboys]

If industrial plants use delta-delta and commercial jobs use delta-wye, thwn what kind of transformer setup is used in multi-family residential buildings?

oh and if a building, say a school has only a switch gear and no transformer, is the power coming straight from the utility?

 

[Pierre C Belarge]

Try reading up about it here.

 

[sparkyboys]

i understand deltadelta is 2:1 and deltawye is 4:1.
So is the utility transformer a delta supply? to the gear? or does there have to be an outside pad transformer before the gear?

 

[sparkyboys]

Or am i just answering my own questions with questions?

 

[augie47]

Pierre's link should answer all you questions.
You will find there is no "given". Preferences by the utility, the customer and the designer dictate and there are many variables.

 

[sparkyboys]

i have read most of that.
two final questions, does the poco bring power to the gear? or just to weather head?

 

[iMuse97]

i have read most of that.
two final questions, does the poco bring power to the gear? or just to weather head?

typically, you bring power to gear. that's the service. assuming a weatherhead as you indicated, around here, I would not want POCO to bring power beyond that point, since that is governed by NEC and under my permit and could be redtagged if not installed correctly.

 

[sparkyboys]

Thanks

Thanks

to all who posted.