I agree with Reno on the rusting out of 'older' items that I see. In a few of the 'older' resi developments (20+ yrs old) there are numerous meter pans that have corrosion issues, & a lot that were replaced already. All are UG services, with the load side exiting thru the back of the meter pan to the panel.
The POCO BUD transformers also are showing rusting. Guess it was a bad period for paint back then!
Ambient temps here swing 100+, and I have not heard of any temp related issues with any exterior main cbs. Meter/main units are very scarce here.
Non-metalic enclosures? Sq D had a 'plastic' pull out HVAC type disco a while back, but I have not seen any recently. A few pool equipment rooms have SS enclosures, and I once had a non-metalic 40 circuit, 120/208, 4 wire panel enclosure fabricated. Pricey....heck yes!
With the newer standards, I feel the 'corrosion' issues for a new install, in a 'normal' atmosphere will be a moot point.
