It is not a detached building, it is outside in the open air at the pool equipment area, run through 2" conduit under the concrete and pops up over by the pool pump to run into the NEMA 3R panel. I couldn't see where I'd need a rod since the ground on the subpanel runs back into the main house and a pool isn't a detached building. Homeowner wants to run a pool heater, some outlets, some lights, and maybe a hot tub (separate from the pool), so putting in 125 amps. The pool area is around 2600SF including the pool, all concrete otherwise though.
So yes, as a detached "structure" it needs the GES. This doesn't get to my initial question which has to do with the grounding wire run from the main panel out to the subpanel though, and the "extruded polymeric" covering that would allow that wire to be Aluminum since it's in a corrosive environment (since it is near a pool). Maybe I'm overthinking the whole "extruded polymeric" thing since pretty much all non-bare wires have some kind of PVC or cross-linked polyethylene covering/insulation around the metal itself, and polyethylene is definitely a polymer.
And therein lay my confusion, it's those incredibly similar initialisms that will get you. No problem to run copper wire as the GEC for the subpanel, my question was about using aluminum ground wire for the EGC, but I'm thinking (now that I've got my letters in the right orders) that based on 680.25(A) there is no exception for aluminum (unlike the exception for use of the extruded polymeric covering in the GEC wire).
It's right by a pool, less than 10' from the pool pump.
If it's for Swimming Pools, Spas, Hot Tubs, Fountains, and Similar, Article 680 applies and imposes its own requirements. Two ground rods probably won't suffice.
