Grounding electrode at exterior light poles

[tom baker]

We've gotten off track here.
The graphic below is what the NEC has to say. Install an auxiliary ground rod if required by specs, or its a slow day. Are there any white papers on the subject, other than the one by Werner, I don't know. You can search the IEEE and if you are a member they are free to download.
Does a ground rod at a lighting pole protect from lightning? Maybe. The Werner article states the reinforcing steel in a concrete foundation is a far better ground than a ground rod, especially the anchor bolts are fastened to the rebar. Installing a ground rod connected by a #6 wire won't do much due to the high impedance of the #6. At lightning frequencies, a 250 KCML copper impedance is not much better than #6. Whats needed is a 4" wide copper strap. And a ground rod will do nothing to clear a fault.
Just make sure you have a EGC back to the source. Upside the EGC use copper compression connectors and SS hardware at the pole connection, Install SPD on the branch circuit at the building entrance
Cell towers are well protected against lightning. One I did had 3 ten foot ground rods, connected with 2/0 copper plus a foundation 10 ft x 10 ft x 4ft with rebar.

 

[don_resqcapt19]

I don't think 250.32 is relevant here as this is equipment, not a structure. As I and others have mentioned, take the case condensing unit on a slab/foundation away from the building. Many larger units have multiple branch circuits feeding them and no GES is required because it is equipment. Likewise light pole could have multiple branch circuits and still not need a GES.

And that is exactly why the definition of structure was changed in the 2017 code to exclude equipment. If you are on an older code, equipment is covered by the definition of structure as equipment is built or constructed.