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Discussion Starter · #1 ·
I need to step up from 3 phase 208 to 480. Everything I find is Delta on the 480 side but my understanding is that in order to ground properly I need Wye on the 480 side. What are my options?
 

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Electrical Contractor
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You can "corner ground" the 480 delta. Are you looking at using a regular step down transformer as a step up? A regular step up transformer is $$$$.
 

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I need to step up from 3 phase 208 to 480. Everything I find is Delta on the 480 side but my understanding is that in order to ground properly I need Wye on the 480 side. What are my options?
If you only need 480 three phase and have no need for 277 volts you can get a 208 delta x 480 delta transformer and bond phase B to ground making it a corner grounded delta system. It is legal but not very popular due to the fact that you will have 480 volts between phase A and C to ground.

Another option may be running it ungrounded but that depends on the application. What exactly are you supplying and what kind of place is it?

And finally you could order a 208Y or 208 Delta primary / 480Y/277 transformer. In my opinion this is likely the best option.
 

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Discussion Starter · #4 ·
It's a commercial building, a slate company. They are installing an industrial saw that has 2 460V motors. I'm not really comfortable with corner grounding, I've heard it creates issues and I'm afraid of someone coming behind me and getting hurt.
 

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Discussion Starter · #5 ·
Wendon, yes I would like to use step down as step up. Customer wants to buy used to save money.
 

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Feyd said:
It's a commercial building, a slate company. They are installing an industrial saw that has 2 460V motors. I'm not really comfortable with corner grounding, I've heard it creates issues and I'm afraid of someone coming behind me and getting hurt.
It is a common procedure and honestly if a person is working on this system and isnt qualified to recognize the hazards then they will eventually kill themselves off in some other way.

But honestly, it's pretty common
 

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...I'm not really comfortable with corner grounding, I've heard it creates issues and I'm afraid of someone coming behind me and getting hurt.
I agree with Pony. There's nothing really unusual or inherently dangerous about this install.

I don't think I've ever seen a 208Δ and I'm not sure such an animal exists (which may be why you're having trouble finding it), but what you can do is a 208Y:480Y and float the neutral in the 208V primary. That will accomplish the same thing.
 
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