Grounding Light Poles

[PhaseShift]

Installing new 35ft concrete light poles. At bottom of poles there is a loop of bare copper ground wire that is tied into rebar etc.. in pole.

Should I drive a ground rod at each of these poles and attache this ground to it. I'm pretty sure it wont help with any fault current but what about lightining? Or should I ignore ground rod and tie into EGC?

Your help is appreciated.

 

[nakulak]

normally we always see a ground rod shown on plans (I guess its for lightning protection ?), but if your ahj doesn't require it, and the plans don't demand it, why put it in ?

 

[PhaseShift]

normally we always see a ground rod shown on plans (I guess its for lightning protection ?), but if your ahj doesn't require it, and the plans don't demand it, why put it in ?

This is an in-house project where we are the designers and installers. We are looking for advice or proper practice and theory on what to do with these?

I'm guessing it would only be beneficial for lightining.

 

[LarryFine]

I would think the concrete itself in contact with the earth is adequate. I also believe the circuit EGC should be tied to this copper wire as well as the pole itself, unless the pole bolts are tied to the rebar.

 

[Cavie]

The powers to be with FDOT require a 20' rod at each pole and tied to the #6 EGC back to the service. There are no lightning issues and we are in the lightning capital of the world.

 

[PhaseShift]

So does grounding the pole with ground rods do anything for lighining? Are we any better off with the ground rods then we would be without them?

 

[raider1]

So does grounding the pole with ground rods do anything for lighining?

IMHO No. Installing ground rods at light poles does nothing to limit the damage from lightning

Are we any better off with the ground rods then we would be without them?

Again IMHO no.

Chris

 

[Cavie]

So does grounding the pole with ground rods do anything for lighining? Are we any better off with the ground rods then we would be without them?

I have no opinion one way or the other having no formal education lightning grounding procedures but as stated in post #5, Central and South Florida is concered the lightning capital of the world and lightning strikes are not an issue with respec to street light poles. There is no connection to the rebare in the precast concrete base.

 

[PhaseShift]

Does anyone have any theory or references to explain why a ground rod may or may not be needed.

If you didn't use a ground rod wouldn't the lighting strike possibly finds its way down the EGC and damage something back in the distribution system?

 

[mcclary's electrical]

Mods,,,,please post Mike's view on this. I read it posted a few weeks ago. I agree with what he said. The concrete base in touch with the earth is a far superior ground than a ground rod. However, I'm basing my opinion on a standard 8' 5/8" rod, that normally is more than 25 ohms to ground. With 20 foot rods, or multiple 12' rods, you MAYBE, MAYBE, by some small, tiny, almost unmeasurable improvement on the already superior ground of mass of concrete and steel in touch with the earth.

 

[sparky=t]

Installing new 35ft concrete light poles. At bottom of poles there is a loop of bare copper ground wire that is tied into rebar etc.. in pole.

Should I drive a ground rod at each of these poles and attache this ground to it. I'm pretty sure it wont help with any fault current but what about lightining? Or should I ignore ground rod and tie into EGC?

Your help is appreciated.

can you elaborate on your install? are you using precat pole bases?
where is the loop of copper? at the pole or the base?

we typically tie our own cages, and pour in place, when doing so we bond to the cage with a #6 solid cu and leave a coil in the tube to it to contact the earth, weigh it down so it does not float up with the flow of concrete, we then leave a tail or loop at the top of the base to bond with the pole and the egc. shortest path to ground wins.

hope this may help, there are many ways and opinions on how to do these.


merry x-mas and happy holidays

 

[bphgravity]

Connecting electrical equipment to earth almost never serves any purpose. The best thing to do is perform a risk analysis versus cost analysis and proceed from there. I would venture to say that a ground rod rod driven next to a light pole will perhaps only provide the most insignifigant of surge mitigation in the area of 1 out of 10 direct strikes. Meaning, 9 out of 10 times, it will serve no purpose. During that one event, the protection will be near unperceivable.

If you are concerned at circuit wiring, I would consider surge protection equipment in lieu of any grounding methods.

 

[PhaseShift]

can you elaborate on your install? are you using precat pole bases?
where is the loop of copper? at the pole or the base?

we typically tie our own cages, and pour in place, when doing so we bond to the cage with a #6 solid cu and leave a coil in the tube to it to contact the earth, weigh it down so it does not float up with the flow of concrete, we then leave a tail or loop at the top of the base to bond with the pole and the egc. shortest path to ground wins.

hope this may help, there are many ways and opinions on how to do these.


merry x-mas and happy holidays

The poles I am referencing are pre-cast poles. The poles are being burried 5ft deep. The poles are cast an have rebar inside. The rebar has a ground wire loop hanging out of the top and bottom of the pole. I was going to tie the top loop into the EGC going to the light. The bottom pole I was going to tie to a ground rod, however now this seems like it is not necessary and may be better off tied to the EGC as well or just left alone.

 

[mcclary's electrical]

The poles I am referencing are pre-cast poles. The poles are being burried 5ft deep. The poles are cast an have rebar inside. The rebar has a ground wire loop hanging out of the top and bottom of the pole. I was going to tie the top loop into the EGC going to the light. The bottom pole I was going to tie to a ground rod, however now this seems like it is not necessary and may be better off tied to the EGC as well or just left alone.

I would take that wire coming out of the concrete into the handhole. I would then wrap a piece of #10 solid around the lug bolt in the hand hole and put on a nut and washer. Bring the #10, the wire from the concrete and the EGC under one wirenut.

 

[PhaseShift]

Thanks for all of the responses guys. Does anybody have any references for not driving ground rods. Folks here keep insisting that we need ground rods for lighting protection. They claim if not lighting will travel back through EGC and damage equipment. I need to prove that ground rod wont help much.