Neutral Grounding Resistor restricted area

[JBUDA54]

I have been requested to design a restricted from entry a Neutral Grounding Resistor (NGR) Area that will house 5 NGR units combined to be 12 ohms from a wye delta grounding transformer (XFMR) [also inside the restricted area]. My question is what is the minimum distance from from my exposed neutral connection to the perimeter fence? What is my code reference to design towards? NESC? NEC? Both state that 10' from live parts to fence is required, but I am wondering if that is for non prohibited access. Is there some execption to a prohibited access area. We are planning on kirk-keying a group operated switch with the padlock of the gate and in addition have signage not to enter while the circuit is energized.

I have been scouring the internet to find some reference to this application. Certainly there are other circumstances, but I am relatively new to the Utility industry. Most of my background is industrial. Thanks for your help, sources, and suggestions!

 

[Smart $]

If you are doing utility work the NEC does not apply unless noted as sych in the project specifications.

Short of the NEC being specified, AFAIK electric utilities at the very least follow NESC requirements.

 

[Ingenieur]

what is the potential?
that should be the determining factor for clearances

 

[JBUDA54]

Potential

Potential

The potential during a fault could be as high as 20kV the L-L is 34.5kV and the L-G is 20kV.

But in a normal unbalanced condition the most it will see before the relay trips is around 600V.

 

[Ingenieur]

20000/12 = 1670 A max fault i
trip at 600 vac
600/12 = 50 A

I'd use the nesc clearance charts for 20k
the max V-G you'll see