Transformer decision.

[frankft2000]

Transformer decision.
Old restaurant completely gutted out to make a office building, panels too.
Utility took old 3 phase transformer out during supply chain problem.
What would be the best 3 phase system to have now for the office, 208 wye or the 240 volt delta?

I’m leaning towards the 240 delta since there will be a small amount of electric heat.

 

[ptonsparky]

208 Wye.
Panels and breakers are readily available. Loads easily balanced. Small amount of electric heat is a non issue.

Search for threads on Deltas.

 

[LarryFine]

Definitely the wye. POCOs may not even deliver high-leg services any more.

 

[infinity]

I agree Wye. Unless for some reason there are large 3 phase loads Delta isn't well suited for an office space.

 

[jim dungar]

I agree Wye. Unless for some reason there are large 3 phase loads Delta isn't well suited for an office space.

Delta generally isn't suited for anywhere.
Utilities like to supply 240/120V 4W delta because they have ready access to center tapped pole mounted single phase transformers.

 

[David Castor]

Another vote for 208/120 V grounded wye. Many utilities in the PNW won't even provide new 240 V wild-leg services. Office will have a lot of 120 V loads and the wye transformer will have more capacity for that.

 

[gar]

230504-1725 EDT

I believe you will find large installations of ungrounded 3 wire delta systems in industrial plants where the goal is to keep the production line running.

..

 

[hillbilly1]

Delta generally isn't suited for anywhere.
Utilities like to supply 240/120V 4W delta because they have ready access to center tapped pole mounted single phase transformers.

Delta is used a lot in industrial, because a lot of foreign equipment is 240 volt, but anywhere else, wye is a much better choice. I’ve got two delta’s to install in a plant in the next couple of weeks. I know the inspector is going to look at it funny, because I had to use Yellow, Brown, Purple for the 480 volt service, because I reserved Orange for the 120/240 delta panel.

 

[jim dungar]

230504-1725 EDT

I believe you will find large installations of ungrounded 3 wire delta systems in industrial plants where the goal is to keep the production line running.

..

Not so much any more.
High resistance grounded system have been gaining in popularity for several decades.
Of course customers that own their MV to LV transformers tend to do what they have always done.