Ground Grid Study
Ground Grid Study
(OP)
If the customer didn't have specific instructions on whether the cacluation be done for a 70 KG or 50 KG person.
Which one is recommended to choose?
Is there a difference of paractice for NEC or CSA point of view?
Which one is recommended to choose?
Is there a difference of paractice for NEC or CSA point of view?






RE: Ground Grid Study
Your best bet is to follow IEEE-80-2000 if this is for a substation application. I assume you are in Canada?
RE: Ground Grid Study
Cost difference between 70 and 50 is another criteria that needs to be considered.
if 70 KG is considered, less copper and Rods will be used.
RE: Ground Grid Study
You would be best served to take the conservative route for the sake of safety than to take the less conservative route for cost.
Have you run any studies yet? Did you have to add a significant amount of buried copper to meet 50kg criteria?
What software are you using? What is the application of this grid?
RE: Ground Grid Study
We use CYMGRD.
RE: Ground Grid Study
RE: Ground Grid Study
If the calculation is done for 70 KG, the touch potential will be higher for a 50 KG person when touching the fence.
RE: Ground Grid Study
If not, I see no justification for using 70 kg inside the substation and 50 kg outside.
RE: Ground Grid Study
makes sense.Thank you.
RE: Ground Grid Study
RE: Ground Grid Study
I agree with the statement of shock time affecting your results. You have to choose one that is realistic, yet conservative enough. We typically use 250 milliseconds.
RE: Ground Grid Study
I beleive this depends on the total clearing time of upstream breaker.
WindTurbines..
Can I ask, based on what assupmtion you use 250ms?
RE: Ground Grid Study
RE: Ground Grid Study
RE: Ground Grid Study
RE: Ground Grid Study