Why ground temps?

[George Stolz]

Edit: Found a picshur!

[ May 12, 2005, 08:11 PM: Message edited by: georgestolz ]

 

[pierre]

Re: Why ground temps?

George
It also helps to keep the earth potential of the area around the temp service at the same earth potential.

250.4(A)(2)

[ May 12, 2005, 08:10 PM: Message edited by: pierre ]

 

[George Stolz]

Re: Why ground temps?

Are they truly effective, or do they just help?

 

[don_resqcapt19]

Re: Why ground temps?

Pierre,

It also helps to keep the earth potential of the area around the temp service at the same earth potential.

But only for a very small area. About 80% of the voltage on the ground rod will be dropped across the earth within 3' or so of the rod.
Don

 

[charlie]

Re: Why ground temps?

George, what do you think would happen if the transformer had a primary to secondary coil failure? Where would the fault current go? That is the part of the statement about contact with higher voltage lines.

If everything works correctly and we didn't have anything miswired, the grounding on your end would not matter. However, the fault current return path will take all available routes and your ground rod will be used.

 

[George Stolz]

Re: Why ground temps?

Ah, primary voltage. That starts to make sense.

Thanks guys.