UPS w/h a 480v to 208v tramsformer

[Capital]

Installing a UPS, 480v primary, Delta/Wye 208v secondary. I am not sure how to land the grounds. Does the equipment ground from the primary land on the XO along with the secondary?

do I need to provide building steel to the XO?

 

[ron]

How is the bypass being handled? Is there a separate static or maintenance bypass transformer or does it use a common transformer as the output transformer.

The IEEE Green Book has some sample diagrams, but the manufacturer likely has the best from their Installation Manual.

Start looking on Page 26 of this Book https://nanopdf.com/download/ieee-std-142-1991-revision-of-ieee-std-142_pdf These images were overly simplified in the 2007 version

 

[don_resqcapt19]

The secondary of the transformer is a separately derived system and the grounding has to comply with 250.30. That will require a GEC to a grounding electrode among other things.

 

[Dale001289]

Installing a UPS, 480v primary, Delta/Wye 208v secondary. I am not sure how to land the grounds. Does the equipment ground from the primary land on the XO along with the secondary?

do I need to provide building steel to the XO?

You can land the transformer primary side equipment grounding conductor on the same grounding terminal bar as the secondary side. The secondary side needs to have a GEC to nearest electrode, building steel is fine.

 

[Capital]

that's how I see it --thank you