Pole Lights and Ground Rods

[tom baker]

And the appropriate reference is article 250.32(A). It starts by saying each separate structure (and a light pole counts as being a structure) shall have a grounding electrode system.

I don't have my electronic version of the NEC available, but there is an exception that lighting poles are not considered structures, otherwise we would have to install disconnects at each one.

 

[iwire]

I don't have my electronic version of the NEC available, but there is an exception that lighting poles are not considered structures, otherwise we would have to install disconnects at each one.

Tom, that is not correct.

Poles remain structures, the exception is directly to the requirement requiring a disconnect. It does not change the GES requirements.

225.32 Location. The disconnecting means shall be installed
either inside or outside of the building or structure
served or where the conductors pass through the building or
structure. The disconnecting means shall be at a readily
accessible location nearest the point of entrance of the conductors.

For the purposes of this section, the requirements
in 230.6 shall be utilized.

Exception No. 1: For installations under single management,
where documented safe switching procedures are established
and maintained for disconnection, and where the
installation is monitored by qualified individuals, the disconnecting
means shall be permitted to be located elsewhere
on the premises.

Exception No. 2: For buildings or other structures qualifying
under the provisions of Article 685, the disconnecting
means shall be permitted to be located elsewhere on the
premises.

Exception No. 3: For towers or poles used as lighting
standards, the disconnecting means shall be permitted to be
located elsewhere on the premises.

Exception No. 4: For poles or similar structures used only
for support of signs installed in accordance with Article
600, the disconnecting means shall be permitted to be located
elsewhere on the premises.

 

[don_resqcapt19]

Actually that exception really makes it clear that the light pole is a structure.

 

[jaggedben]

In this whole thread I don't believe anyone has mentioned that if the pole itself is metal and goes 10ft in the ground, it can be its own electrode and definitely no ground rod is required.

I certainly agree that if the pole meets the requirements then adding a ground rod will do zilch.

Lightning protection is a whole other code.

 

[kwired]

In this whole thread I don't believe anyone has mentioned that if the pole itself is metal and goes 10ft in the ground, it can be its own electrode and definitely no ground rod is required.

I certainly agree that if the pole meets the requirements then adding a ground rod will do zilch.

Lightning protection is a whole other code.

But they are typically attached to a concrete base. Said base may not quite qualify (per NEC) to be a CEE, but many still believe what is there is likely a better electrode in majority of cases then a typical 8 foot ground rod is.

 

[kwired]

And the appropriate reference is article 250.32(A). It starts by saying each separate structure (and a light pole counts as being a structure) shall have a grounding electrode system. It then gives an exception that says you don't need a grounding electrode system if the structure (light pole) is fed from a single circuit (including, if appropriate, a multi-wire branch circuit) that includes an equipment grounding conductor. That is why Bob's statement about more than one branch circuit or a feeder is correct.

I don't have my electronic version of the NEC available, but there is an exception that lighting poles are not considered structures, otherwise we would have to install disconnects at each one.

Unless the pole light is supplied by more than one branch circuit, or a feeder the NEC does not require a grounding electrode at the pole.

First two quotes were comments following the last quote here.

There is also the exception following 250.32(A) that fits into this conversation if the light pole is only supplied by a branch circuit:

Exception: A grounding electrode shall not be required where only a single branch circuit, including a multiwire branch circuit, supplies the building or structure and the branch circuit includes an equipment grounding conductor for grounding the normally non—current-carrying metal parts of equipment.

 

[jaggedben]

But they are typically attached to a concrete base. Said base may not quite qualify (per NEC) to be a CEE, but many still believe what is there is likely a better electrode in majority of cases then a typical 8 foot ground rod is.

As long as the pole goes 10ft into the ground, it's an electrode. Concrete doesn't matter. Code says 'with our without concrete encasement'. 250.52(A)(2)(1).

I suppose in many cases it may be cheaper and require less logistical organization to just drive a rod than to increase your digging depth to 10ft for the pole base, or to build bases with CEEs in them. I was just sayin' what the code allows.

 

[iwire]

I have never seen a metal pole direct buried other than a home post light.

 

[jumper]

As long as the pole goes 10ft into the ground, it's an electrode. Concrete doesn't matter. Code says 'with our without concrete encasement'. 250.52(A)(2)(1).

I suppose in many cases it may be cheaper and require less logistical organization to just drive a rod than to increase your digging depth to 10ft for the pole base, or to build bases with CEEs in them. I was just sayin' what the code allows.

Isn't this rather a moot point since a GE is not required?

 

[mgookin]

Isn't this rather a moot point since a GE is not required?

Not required only if on a branch circuit in which you pull a EGC.

Depending on the run and conductors, it may be cost favorable to pound the rod. No? Yes? Maybe?

 

[jumper]

Not required only if on a branch circuit in which you pull a EGC.

Depending on the run and conductors, it may be cost favorable to pound the rod. No? Yes? Maybe?

Pound the rod for what? What benefit?

A GES is not a substitute for an EGC.

 

[cpinetree]

I have never seen a metal pole direct buried other than a home post light.

Just quoted a job with direct burial aluminum posts (35' overall)
Link to Hapco round direct bury Aluminum poles: http://www.hapco.com/products.php?view=poles&style=RTA&basestyle=Embedded

Have a job this week setting a 35' fiberglass / composite direct burial pole.

No grounds rods for either job

 

[iwire]

Maybe a regional thing, here everything gets a concrete base. Likely due to winter.

 

[GoldDigger]

Maybe a regional thing, here everything gets a concrete base. Likely due to winter.

Another reason, for poles on or near a vehicular path, is to provide a breakaway joint to reduce injury when the pole is hit. Without it the pole can either come down very hard on top of the car or cause a major incursion into the front.

 

[iwire]

Another reason, for poles on or near a vehicular path, is to provide a breakaway joint to reduce injury when the pole is hit. Without it the pole can either come down very hard on top of the car or cause a major incursion into the front.

Maybe but we install many conreate bases at grade level.

 

[GoldDigger]

Maybe but we install many conreate bases at grade level.

Not in California. There is a limit to the height above ground of the concrete base.
Direct buried wood posts have horizontal holes bored near the base to create a weak spot.

 

[tom baker]

Tom, that is not correct.

Poles remain structures, the exception is directly to the requirement requiring a disconnect. It does not change the GES requirements.

The intent of this exception, thanks for finding it, was to clarify that a disconnect is not required at each pole, I have seen pictures of poles with fused discos on each one

 

[kwired]

As long as the pole goes 10ft into the ground, it's an electrode. Concrete doesn't matter. Code says 'with our without concrete encasement'. 250.52(A)(2)(1).

I suppose in many cases it may be cheaper and require less logistical organization to just drive a rod than to increase your digging depth to 10ft for the pole base, or to build bases with CEEs in them. I was just sayin' what the code allows.

The pole usually isn't in the ground though, just connected to some anchor bolts embedded in the base. There is often rebar in the base but I don't know that it typically would qualify as a NEC recognized CEE, but I still believe in many cases will have less resistance to earth then a ground rod.

 

[iwire]

Not in California. There is a limit to the height above ground of the concrete base.
Direct buried wood posts have horizontal holes bored near the base to create a weak spot.

So no standard telephone poles?

In thinking of this some more, some of the cites and towns near me do use direct burred concrete poles for street lights. Just have never seen direct buried metal ones in this area.

Here if the lighting pole is out in the open of a parking lot we will use a raised base, however if it is in an island or outside the curbs along the edges it will often be down at, or a few inches above grade.

 

[jumper]

In thinking of this some more, some of the cites and towns near me do use direct burred concrete poles for street lights.

Direct buried concrete poles are common enough here, steel-nope.