Ground rod in every light pole?

[tortuga]

Now that voltage drop is a code requirement in most states I have seen huge increases in wire sizes.
Recently I saw a set of prints that had #1 Al on a 60A breaker for parking lot lighting.

 

[tom baker]

You would have thought their monthly utility bill would have tip them off.

Some lighting systems are flat rate with no meter

 

[tom baker]

Now that voltage drop is a code requirement in most states I have seen huge increases in wire sizes.
Recently I saw a set of prints that had #1 Al on a 60A breaker for parking lot lighting.

I had had some hwy maintenance tech from Wyoming in a class where they ran 120 for 1/2 Mile and used 250 al

 

[Joethemechanic]

Some lighting systems are flat rate with no meter

Yeah I had one of those installed by PP&L back in 2016. Three poles and lights installed at the far end of my lot. Twenty bucks per month for each light. It was great until they changed to low energy LED lights. Not only were they dim, but they were a different design and didn't throw the light were I wanted it. In fact 2 of them were lighting the property next door better than mine. They wouldn't fix it, so I canceled after the 2 year agreement. They actually came and took the lights, but left the poles

 

[User Name]

I'm a little late to the party...had a customer have their parking lot lights nuked from lightning here about the same time as the OP's first post. 25' steel poles on precast concrete bases. No ground rods, the lightning hit one of the lights, melted the aluminum housing, proceeded to blow the insulation off all the wiring down the pole, 100 feet to the next pole, up that pole, and another 30 feet to the main panel and blow that up. It also blew up a bunch of stuff 200 feet away in the adjacent building that this is all feed from.

Do I think ground rods at each pole would have helped? On one hand I feel like it maybe would have maybe isolated some of the damage to maybe the first pole or maybe second. On the other hand I think that lightning has so much energy there's nothing you're going to do to stop it.

I've been told too you don't want to connect a ground rod to a wire smaller than your GEC at your service, as you could create a path to ground on wire that isn't sized for the job. So maybe just running your EGC from pole to pole and calling it good is the way.

 

[ptonsparky]

I'm a little late to the party...had a customer have their parking lot lights nuked from lightning here about the same time as the OP's first post. 25' steel poles on precast concrete bases. No ground rods, the lightning hit one of the lights, melted the aluminum housing, proceeded to blow the insulation off all the wiring down the pole, 100 feet to the next pole, up that pole, and another 30 feet to the main panel and blow that up. It also blew up a bunch of stuff 200 feet away in the adjacent building that this is all feed from.

Do I think ground rods at each pole would have helped? On one hand I feel like it maybe would have maybe isolated some of the damage to maybe the first pole or maybe second. On the other hand I think that lightning has so much energy there's nothing you're going to do to stop it.

I've been told too you don't want to connect a ground rod to a wire smaller than your GEC at your service, as you could create a path to ground on wire that isn't sized for the job. So maybe just running your EGC from pole to pole and calling it good is the way.

Direct hit? Skyscrapers are hit often enough, use whatever they use. Otherwise have insurance.

 

[User Name]

Yup direct hit. Good insurance is the key.

 

[tortuga]

I'm a little late to the party...had a customer have their parking lot lights nuked from lightning here about the same time as the OP's first post. 25' steel poles on precast concrete bases. No ground rods, the lightning hit one of the lights, melted the aluminum housing, proceeded to blow the insulation off all the wiring down the pole, 100 feet to the next pole, up that pole, and another 30 feet to the main panel and blow that up. It also blew up a bunch of stuff 200 feet away in the adjacent building that this is all feed from.

Do I think ground rods at each pole would have helped? On one hand I feel like it maybe would have maybe isolated some of the damage to maybe the first pole or maybe second. On the other hand I think that lightning has so much energy there's nothing you're going to do to stop it.

I've been told too you don't want to connect a ground rod to a wire smaller than your GEC at your service, as you could create a path to ground on wire that isn't sized for the job. So maybe just running your EGC from pole to pole and calling it good is the way.

Thats unfortunate about the poles, when experts discuss lighting and the NEC its often pointed out that since lightning protection is a different NFPA standard and 90.1 of the NEC defines the scope of the code, that its not really our job to consider.
I know there are lighting protection experts out there I have been on jobs with a few and they love ground rods at poles, ground rings and all kinds of stuff, they also use a different type of grounding wire, flat and braided.
Just look at how radio and cell towers are built.
With all the experts we have on this forum I am surprised we dont have a lightning protection one on here?

I do still find it a shortfall of the code, particularly article 225, that a pole, vault or manhole cover can be so far from a OCPD that it can be ground faulted and energized and still be code compliant unable to trip a breaker.

 

[don_resqcapt19]

....

I do still find it a shortfall of the code, particularly article 225, that a pole, vault or manhole cover can be so far from a OCPD that it can be ground faulted and energized and still be code compliant unable to trip a breaker.

If there is a way to fix that, the system is open for the submission of PIs to make changes for the 2026 code. Not sure there really is a way to fix that for very long distances on a grounded system.

 

[rambojoe]

Of course lightning experts love rods and rings...
The cheddar in the mousetrap is always free... until it's not, I guess.

 

[rambojoe]

If there is a way to fix that, the system is open for the submission of PIs to make changes for the 2026 code. Not sure there really is a way to fix that for very long distances on a grounded system.

One still has to wonder why all the fuss.
We could agree that it's not for the safety of personal..
Get out of the storm!
Other than that, screw the light pole...

 

[Joethemechanic]

Just look at how radio and cell towers are built.

Reminds me of this thing that happened in my town when I was a kid. This ham radio operator put up a 229 foot tower in the backyard at his house. No zoning, no permits, no inspections, nothing. It wasn't a big yard either. I wonder how that was grounded. It must have been done right because it's 50 years old and still standing.

Funk v. Township of Bensalem, 17 Pa. Commw. 205 (1975)​

https://cite.case.law/pa-commw/17/205/

 

[ActionDave]

Just look at how radio and cell towers are built......

The "grounding" at cell towers is more about bonding every conductive part back to a central point to a central point so there is no difference in potential between any point throughout the site.

 

[Joethemechanic]

What abought radio towers that sit on insulators and the whole tower is actually the antenna? How could they be grounded?

 

[winnie]

What abought radio towers that sit on insulators and the whole tower is actually the antenna? How could they be grounded?

They have large spark gaps set up to couple transients directly to the grounding system.

Just like any other circuit element, an antenna system requires two terminals. The other terminal of the sort of antenna is a very good grounding electrode system. Often consisting of copper radials in the ground over an extensive area. Much better than required by NEC or for lightning protection, the grounding system is required for efficient RF transmission.

Jon

 

[User Name]

If there is a way to fix that, the system is open for the submission of PIs to make changes for the 2026 code. Not sure there really is a way to fix that for very long distances on a grounded system.

Maybe either a fuse holder in each pole, or a 2 pole breaker panel at each pole....or maybe a gfci outlet on each pole feeding up the pole?

 

[rambojoe]

Maybe either a fuse holder in each pole, or a 2 pole breaker panel at each pole....or maybe a gfci outlet on each pole feeding up the pole?

That is the best idea i heard yet...
Im for 24k anchor bolts as well for aero-space grade conductivity to all that concrete!

 

[Joethemechanic]

They have large spark gaps set up to couple transients directly to the grounding system.

Just like any other circuit element, an antenna system requires two terminals. The other terminal of the sort of antenna is a very good grounding electrode system. Often consisting of copper radials in the ground over an extensive area. Much better than required by NEC or for lightning protection, the grounding system is required for efficient RF transmission.

Jon

I was kind of thinking maybe spark gaps, Although I would still think you would get damaging currents flowing back to the transmitter. I know about the grounding radials from experimenting with vertical ham radio antennas. In fact that limited my vertical antenna builds to the 40 meter band. At the time I just didn't have the space for longer radials.

 

[kwired]

I had had some hwy maintenance tech from Wyoming in a class where they ran 120 for 1/2 Mile and used 250 al

1/2 mile is common around here for some irrigation setups. Is usually 480 volts and/or 120 volt signal conductors though.

 

[jaggedben]

Maybe either a fuse holder in each pole, or a 2 pole breaker panel at each pole....or maybe a gfci outlet on each pole feeding up the pole?

Some kind of GFCI for the whole circuit, or what they call residual current device in most countries, would be pretty simple and effective.