Primary and secodary grounding and bonding of single phase transformers

[FDT]

When installing a single phase transformer, primary is 480v, secondary is 120/240v, it's not quite clear to me as to the grounding issue. If I bring in a ground from the 480v supply, where do I terminate it in the transformer enclosure since I for sure have to ground the secondary and terminate it by use of a ground rod? I would not think that both termination points within the transformer enclosure would be the same since this will then create a ground loop between the new ground rod for the transformer and the ground rod from the tranformer primary feeder.

 

[George Stolz]

Welcome to the forum. Read the ground and bonding sticky thread. Electricity seeks all paths back to it's source, so all grounds touching doesn't result is objectionable current.

All grounds land to XO, and bond to transformer casing.

 

[augie47]

This might help:

 

[electrofelon]

When installing a single phase transformer, primary is 480v, secondary is 120/240v, it's not quite clear to me as to the grounding issue. If I bring in a ground from the 480v supply, where do I terminate it in the transformer enclosure since I for sure have to ground the secondary and terminate it by use of a ground rod? I would not think that both termination points within the transformer enclosure would be the same since this will then create a ground loop between the new ground rod for the transformer and the ground rod from the tranformer primary feeder.

Remember "Ground" is a homonym - same word with multiple meanings. In the context of transformers, we are (usually) equipment grounding AND system grounding - two totally different things and purposes.