# Corner grounded delta system



## CoolWill (Jan 5, 2019)

The first pic is what it would look like if that is a utility transformer. 



The second pic is one possible configuration if it is a separately derived system.


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## Malywr (Jan 23, 2018)

CoolWill said:


> The first pic is what it would look like if that is a utility transformer.
> 
> 
> 
> The second pic is one possible configuration if it is a separately derived system.




It is step up transformer separately derived system . When I upload pictures first become second and second picture is first sorry for confusion if it is.


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## CoolWill (Jan 5, 2019)

Malywr said:


> It is step up transformer separately derived system . When I upload pictures first become second and second picture is first sorry for confusion if it is.



As it is uploaded, the second pic is fine for a separately derived system.


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## Malywr (Jan 23, 2018)

Malywr said:


> It is step up transformer separately derived system . When I upload pictures first become second and second picture is first sorry for confusion if it is.




I missed it is primary 3PH Y208V - delta 480V 3PH secondary step up dedicated for oven 3PH. 

Please help me if grounding and bounding is correct. Grounded conductor in disconnect is separate from EGC (on picture it might look like they are connected )


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## splatz (May 23, 2015)

Malywr said:


> Please help me if grounding and bounding is correct. Grounded conductor in disconnect is separate from EGC (on picture it might look like they are connected )



I was wondering about that. If the grounded conductor isn't separated from the EGC in the disconnect, all the neutral current would be on the EGC from the disconnect to the transformer.


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## CoolWill (Jan 5, 2019)

Malywr said:


> I missed it is primary 3PH Y208V - delta 480V 3PH secondary step up dedicated for oven 3PH.
> 
> Please help me if grounding and bounding is correct. Grounded conductor in disconnect is separate from EGC (on picture it might look like they are connected )
> 
> ...



At the transformer, the grounding electrode conductor, grounded phase, and equipment grounding conductor all tie together. From there a grounded phase conductor and equipment ground go to the disconnect and remain separate. Equipment ground bonds to disconnect and grounded phase connects to unfused pole.


Also, you can save some money by using a two pole disconnect with a neutral bar instead of a three pole, since the grounded phase isn't required to be opened in this situation. You just have to make sure the two pole disconnect is rated for it. I know that the Square D and Siemens brands are, last I saw.


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## lighterup (Jun 14, 2013)

:notworthy::notworthy:


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## CoolWill (Jan 5, 2019)

lighterup said:


> :notworthy::notworthy:


Soak it up while it lasts:vs_mad:


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## Wiresmith (Feb 9, 2013)

Just something to point out, if you use a two pole for the three phase load, the disconnect will require higher current rating than if you switched all three.

Edit: I think, I might be wrong, check the single phase switch is rated at the current with three-phase


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## CoolWill (Jan 5, 2019)

Wiresmith said:


> Just something to point out, if you use a two pole for the three phase load, the disconnect will require higher current rating than if you switched all three.



Why?


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## Wiresmith (Feb 9, 2013)

Arcs divided among two blades instead of three

Edit: I may be wrong but check switch for three phase current rating not the single phase rating


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## Malywr (Jan 23, 2018)

Wiresmith said:


> Arcs divided among two blades instead of three
> 
> Edit: I may be wrong but check switch for three phase current rating not the single phase rating




Thank you for that suggestion I have 3 Pole disconnect and grounded phase has no fuse. Ungrounded 2 phases have fuses


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## Malywr (Jan 23, 2018)

Thank you everyone I really appreciate your help. 


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