Main service tieback has standard three wire, service drop is in conduit to meter of four unit apartment. Service run inside home is to long, close to 20 feet to 200 amp square D box in basement. When dead panel is removed it reveals two neutrals, or am I missing something? Exterior disconnect box was not opened because I could not break the screws free. Updated in 1998. What do you guys see?
Look at it this way. Your two outside wires are the common two you see in a regular residential panel, and your middle wire appears to be just a ground coming from the transformer etc…
It is a 4 wire feed to the inside remote distribution panel from the service disconnect outside, no?
But, it looks like the grounded conductors are not isolated with that jumper wire touching the grounding conductor and possibly the can…needs repair.
That’s 4 wire SER type of SE cable which would be required since this is considered a sub-panel. That is due to the disconnect being on the outside. That means that the SE Cable can run an unlimited length within the structure. The neutral conductors and the EGC’s should be separate within the panel which they appear to be. The bare copper conductors should be removed since they serve no purpose and may inadvertently ground the neutral to the panel enclosure. The two neutral bus bars should be mechanically connected through a piece of buss that is connected to the grayish looking neutral conductor in the center.