480-240 single phase ground point

[dm9289]

On a single phase 480-240 v transformer supply utilization equipment that does not carry a neutral.

Would it be proper to ground the X2-X3 junction like a typical 120/240 system.

Would it be proper to ground X4.

Would one be more advantageous than the other in this application

Please see pic

 

[LarryFine]

Yes, definitely.

You could, but why?

The former in most cases.

 

[dm9289]

Yes, definitely.

You could, but why?

The former in most cases.

 

[dm9289]

I was trying to think of fault current and to my imperfect thinking I thought either could be ok.

If I am correct you recomend X2-3 junction

 

[LarryFine]

I was trying to think of fault current and to my imperfect thinking I thought either could be ok.

If I am correct you recomend X2-3 junction

An end-grounded arrangement would double the line-to-ground voltage, increasing fault current.

I do, for all the usual reasons.

 

[dm9289]

An end-grounded arrangement would double the line-to-ground voltage, increasing fault current.

I do, for all the usual reasons.

Thank you very much great explanation. I felt both gave a path, but did not think of the increased fault current on corner ground.

 

[ptonsparky]

Thank you very much great explanation. I felt both gave a path, but did not think of the increased fault current on corner ground.

It's not a corner ground.

 

[dm9289]

It's not a corner ground.

Thanks that is bad terminology. I guess corner would be a more correct term for corner grounded delta

 

[infinity]

I agree use X2 and X3 for connection of the SBJ.

 

[dm9289]

I agree use X2 and X3 for connection of the SBJ.
View attachment 2569747

Thanks great picture. Mine are usually loaded with dust

 

[Frank DuVal]

The other reason for grounding the center tap (X2-X3) is to limit the line to ground voltage to 120. This is because lots of things that might work on 240 do not like 240 line to ground due to transient protection, etc.

 

[dm9289]

The other reason for grounding the center tap (X2-X3) is to limit the line to ground voltage to 120. This is because lots of things that might work on 240 do not like 240 line to ground due to transient protection, etc.

Thank you