eq gr

[bob]

Re: eq gr

Tom
Thats the program I use. It was actually developed at Ga Tech (nit pick I know).
Dr. A. P. Sakis Meliopoulos was the guy who investigated this problem. I got to know him and
has a number of conversations about this software. The caculations using just an EGC are not to complex but when you try to use steel conduit the caculations are very complex. It has to do with the magnetic fields and its effect on the steel.

 

[bob]

Re: eq gr

Pierre
[QUOTE Would this not create a ton of havoc between inspectors and ECs?[/QUOTE]

Yes it would. This problem seems to lack attention by those in this field. If we are to adhere to 110.10 and 250.4(5) we need to get a handle on this problem.

[QUOTE I believe that the EGC is the most important facet of most any circuits we install, but there is not enough guidance to help us to determine in the field what is and is not effective. [/QUOTE]
I agree that it is important. I hope that everyone will check this program out and see if it can help.

[ February 28, 2006, 04:10 PM: Message edited by: bob ]

 

[don_resqcapt19]

Re: eq gr

Bob,

Since this motor has a FLA of 32 amps, wouldn't the breaker be sized at 70 amps and require a #8 egc to start with?

You may be correct in this case, but if the short circuit and ground fault protective device for the motor circuit is a MCP or instantaneous trip device, then 250.122(D) permits the EGC to be sized based on the rating of the motor overload device.
Don

 

[bob]

Re: eq gr

Don
Thanks for clearing that up for me.