I have a HO that needs his Zinsco main panel replaced.(he works for a insurance co.) Zinsco has a 100 amp backfed main, I was originally trying to see if he only needed a panel swap and not have to change the riser and meter base, which is a round base (60a?), He said later he might want to add Solar and a car charger. his load is only 64 amps even with a 30a 240v charger included, 814 sq. ft. living space. Maximum solar roof space is 20x40 for 800 sq. ft. or 23amps backfeed or 30amp breaker based on calcs from online, estimators. So I figure I need to put in a 125amp bus panel with 100amp and still be under the overdrive rule. My question is do I have to make sure the meter socket can handle 150 or ok with the round base and 100amp aluminum #2 conductors?
The "round base" is rated for only 60 amps. Sounds like you need a complete service upgrade.
"Panel swap" is an obscene term to me. IMO, EVERY "service change" includes bringing it all up to current code - meaning a larger service, a 2" (or larger) mast, a new meter socket, and new ground rodS.
Different factors went in to going down the repair/replace road rather than whole new service, panel width, top feed section on right not left as most I've seen, and UG/OH distribution is tight on most panels or they are double wide.....it wasn't until the idea of solar that I had to look at bussing...access to riser path is challenging, might have to rent a bucket....
That's a perfect application for an "all in one" panel. The existing meter base is only rated for 60 amps, and the new service will have to be at least 100 amps.
The mast might be a problem. I would hope you can relocate the drop, and punch the new mast straight through the eave. Here's where you pay extra-close attention to your PoCo specs; they often specify the drop has to be within a certain distance of the corner of the house.
Don't forget to add ground rods; that service most likely has only a water bond.