The panel (I'm not calling it "service equipment" because it is not allowed for use that way as "service equipment") is a 3 phase panel.
That said, that's a single phase service entering it.
The larger phase conductor in the middle typically is (when a three phase panel is used for single phase) installed on the right and left main lugs, leaving the center phase bus not used. But ... one could chose to use any two of the three buses for the mains, and who ever wired that chose the left and the center.
It looks like, for whatever reason, the left phase conductor was abandoned (not properly) and another smaller phase conductor installed.
I am basing the above on the fact that this looks old and the abandoned phase conductor looks like it was abandoned more recently, meaning it worked well for many years. (An assumption I am making.)
In that case (*IF* that is the case), why was the phase conductor replaced with that small one? The only conductor the person who screwed with this had laying around handy?
Did you measure voltages?
Whenever I would find something 'unusual' in anyway like that, I would measure voltage, to try to figure out if they had 120/240, 120/208, I've even been known to stick my volt meter probe down into those abandoned wires to see what voltage they had on them.
There are WAY TOO MANY breakers (you have to count the empty slots too, because they *could be used* in the future) for this to be proper "service equipment".
However, in reality, *IT IS* being used as the service equipment, so the number of main disconnects (I count about 24 potential disconnects in there) is really all screwed up - from day one, long before that phase conductor was abandoned.
Notice the seal missing from the meter? Did you pee in there? Is it missing *because you did*?
Maybe I'm just to used to prying and peeking into place I should not?
