4/0 copper feed from meter to panel, 8 total breakers in this panel including a 150 amp disconnect for the panel directly to the right, (not pictured), fed with 2/0 copper, the neutral is visible as it is double tapped at the neutral lug for pictured panel. Is there any way to know what size the service amperage is?
There is no main disconnect. No disconnect at the exterior meter panel (picture 1). Only disconnect is a 150 amp breaker with 2/0 copper (bottom of picture 2) that feeds distribution panel to the right of this panel (picture 3).
That is why I am having difficulty finding the service amperage. Note that the two 2/0 neutrals are double tapped at the main panel in the OP. This is the first time I’ve ever seen 4/0 copper in a panel. It was not marked 4/0 copper, but was noticeably larger than the 2/0 copper.
4/0 CU is rated for 225 amps, but it’s unlikely that panel is rated that high. The panel rating would be the limiting factor, but absent a service-disconnect, the point is moot. The installation needs to be corrected.
My guess would be it is a 200 amp, if that is what both the boxes are set up for. Looks like the service panel has a 150 amp breaker for the interior distribution panel.
Those other breaker probably feed the AC, Pool, or other outside items.
It would be rated the same as the breaker in the main panel serving the sub, may be using over sized wire which is fine( service to the sub looks to me like it originates from the breaker in the main) Therefore the sub can not be more than the breaker that serves it.