Small Guard shack ground Rod debate

[Fred B]

Thanks for all the responses and insight. I am curious how others would interpret a light pole that has 'other circuits that spliced in it but continue to feed other poles, but only 1 circuit actually powers that specific pole light. Also another scenario, a circuit supplies the light on the pole but another circuit supplies other equipment on the same pole, for example a camera (including low voltage of 30volts), or some other equipment that has 120v or more. Is a GES still required?

I think poles are exempt from any GES requirements.

Most poles are not a feeder setup just a branch circuit to the pole structure so a GES wouldn't be needed at the pole. If one of the poles has a feeder and a panel with over current devices it then falls as a "structure" and needs a GES.

Mike has a video that discusses this:

 

[brother]

I think poles are exempt from any GES requirements.

Is that in the NEC? I may overlooked it.

 

[LarryFine]

Is that in the NEC? I may overlooked it.

Look instead for a requirement.

 

[tortuga]

Most poles are not a feeder setup just a branch circuit to the pole structure so a GES wouldn't be needed at the pole. If one of the poles has a feeder and a panel with over current devices it then falls as a "structure" and needs a GES.

Mike has a video that discusses this:

Good video, and you can tell he is passionate about the subject.
In the video he talks about a line to ground fault at a remote pole and uses a 20A 120V circuit and 25 ohms ground rod resistance to determine how much fault current would flow thru the earth 120/24 = 4.8A.
I don't think he gets into the distance in the video but as the distance from a fault to the rod increase so does the resistance.
The light pole in the video was metal and had no effective fault current path but did have a ground rod.
If you want to protect from a scenario where a line to dirt fault and no bonded metal parts in the vicinity to contact with the short then you'd need something that offers more protection than a standard breaker can offer, like a GFCI or GFPE breaker.
And then you'd probably want a ground reference for the GFCI to be able to pick up such a fault.

 

[don_resqcapt19]

I think poles are exempt from any GES requirements.

I think you are thinking of the disconnect exception for poles in Exception 3 to 225.31(B). The GEC for poles follows the general rules, but there is a debate on a pole being a structure or being equipment.

 

[petersonra]

I think you are thinking of the disconnect exception for poles in Exception 3 to 225.31(B). The GEC for poles follows the general rules, but there is a debate on a pole being a structure or being equipment.

I thought the rule was changed so poles are exempt from GES requirements.

 

[don_resqcapt19]

I thought the rule was changed so poles are exempt from GES requirements.

only if the AHJ says they are equipment and not a structure.

 

[petersonra]

only if the AHJ says they are equipment and not a structure.

I am pretty there is either an exemption for poles somewhere or poles are defined as equipment.

Or I could be completely wrong.

 

[don_resqcapt19]

I am pretty there is either an exemption for poles somewhere or poles are defined as equipment.

Or I could be completely wrong.

I am not aware of either in the code...only the exception for a disconnect that I cited earlier. Note that the exception is in Part II of Article 225, and the fact that it is in that location very strongly suggests that the Code Making Panel for Article 225 sees the poles as structures.

 

[TX+ MASTER#4544]

Ran into an existing situation where they have a small guard shack (7x5 possibly) with a small 125amp panel with about 4 circuits in it (lights receptacle and special for air conditioner). They ran a 30 amp feeder to it, single phase 2 hots, neutral and ground.

I was under the impression since they ran more than 1 circuit to it and its technically a seperate structure and it sits out in the open in the weather in the parking lot, then it was suppose to have its own ground rod etc.. for lightning and overvoltages. Others say, no it does not since its just a small shack. Never thought the size made a difference for guard shacks. I dont have my code with me at the moment, but am I correct on this? NEC 2024 250 somewhere in there? Doubt if it gets changed, but just double checking myself. Am I correct on this?

2023 NEC
If "they " ran a 30 amp feeder to it then it's not a service. The feeder originates at the service and runs to your small panel. Size doesn't matter for guard shacks. Most guard shacks are unoccupied here in the 21st century and were replaced with "arms" and threatening signs. And the guards kept their arms.

So if there's a meter fed from a utility provider to a main enclosure with a SE label, then that's where you would do all your grounding and bonding there at the service entrance enclosure with a ground rod and a rod at the subpanel and isolate the neutrals from the EGCs there at that enclosure.

The feeder raceway should contain an EGC sized per 250.122 and the Table 250.122 based on the rating of the circuit breaker feeding the subpanel.

Thanks for reading.
Comments accepted.
TX+MASTER#4544

 

[J2H]

I may be out in left field here, but I continue to wonder when I see threads like these if some of today’s grounding requirements as well of the perceived effectiveness of ground rods may have stemmed from the days when the typical grounding electrode was a water main and not a ground rod.

It seems that such a grounding electrode where there was a municipal water supply would be effective at maintaining near zero volts potential if the neutral since the neutral current could return to source through the water main via a neighbor’s neutral for example.

Perhaps the requirement has stayed with the shift to nonmetallic piping without considering the theory of why a water main was so effective, not so much because it was in contact with earth, but because of its massive distance and the fact that it was effectively bonded to the neutral for miles.

 

[don_resqcapt19]

2023 NEC
If "they " ran a 30 amp feeder to it then it's not a service. The feeder originates at the service and runs to your small panel. Size doesn't matter for guard shacks. Most guard shacks are unoccupied here in the 21st century and were replaced with "arms" and threatening signs. And the guards kept their arms.

So if there's a meter fed from a utility provider to a main enclosure with a SE label, then that's where you would do all your grounding and bonding there at the service entrance enclosure with a ground rod and a rod at the subpanel and isolate the neutrals from the EGCs there at that enclosure.

The feeder raceway should contain an EGC sized per 250.122 and the Table 250.122 based on the rating of the circuit breaker feeding the subpanel.

Thanks for reading.
Comments accepted.
TX+MASTER#4544

Thanks for another apparently AI reply that has absolutely nothing to do with the thread.