Most Apartments I ran into most useally have main breaker right below or next to the meter socket however you have to watch out the numbers of meters if more than 6 then you must installed a master or super main breaker / fuse before meter stacks or meter bank.
Once you have main breaker at the meter location and run 4 conductor to the apartment load center you don't need the main breaker at that location unless you got riser system now that is diffrent game to deal with it.
Merci,Marc
