I have been wanting to upgrade from 150 service panel to a 200 service for future expansion. I spoke with an electrician over the phone and he told me that my 150 service panel was a mistake. The main break is 150 amp and he thinks that is was probably a 100 service with an over sized breaker. Does anyone come across this size panel or is the norm. 100 and 200 service. The wire entering is 2/0 Al. What do you think? Thanks.