grounding grid observation profile in CDEGS 3

[alone021]

Hello,

IEEE std 80-2013 mentioned grounding grid is normally set 3-4 feet extension out of the station fence boundary. And in CDEGS, the observation profile is set at another 3 feet extension out of the grounding grid boundary.

My question is if there is any colorful spots shown on the outer 3 feet area, which means in grounding grid area, including inner fence are ALL clear without any touch potential issue, and we are sure there is no equipment or building or structure there, could we simply ignore those colorful spots in grounding study?

grid is attached, and the pink stuff is fence.

Thank you

 

[DBL-E]

You are understanding IEEE 80 correctly, if there is nothing to touch there is not a touch hazard (even if software indicates the potential is there). You can ignore the colorful spot, but I want to highlight common oversights-
-- Is there surfacing (rock) considered in the compliance criteria (if yes does it go out to 3-4 feet)?
-- Are there any outward swinging gates that may extend the reach from ~3 feet to 10 foot gate + 3 foot reach (13 foot total in this example)

 

[huskyeng]

You can set the profile to only run the simulation in the bounds of your grid, then you won't see any of the issues outside.

 

[alone021]

Thank you, DBL-E, and Yes, there is crushed rock covers beyond 3 feet of grid.

So it is OK to not observe this extra 3 feet of crushed rock area?

The project is in Canada, so CSA C22.1 36-304 also applies here, which asks to have 1 meter extend out of grid. So I am just wondering if the profile in CDEGS has to observe this extra 1 meter out of grid? now it seems we can just run the simulation in the boundary of the grid, then we won't see any of the issues outside---it compliances with both IEEE 80 and CSA C22.1, right?

 

[alone021]

Thank you, huskyeng, yes, so only observe the grid area, not see any of the issues outside---does it compliance with both IEEE 80 and CSA C22.1 36-304?

 

[jghrist]

If step-voltage can be a problem (usually not), you should consider 1 meter outside the grid. This is where the step-voltage is greatest.