What your photo is showing is that the black conductor re-identified with "YELLOW" phase tape is the neutral conductor, which should have been re-identified with "white" phase tape. That is one problem, albeit a minor problem.

The other black conductor, which is not re-identified, is the hot phase conductor ... "one single" hot phase conductor ... which indicates that the upstairs unit is only fed with a 120 volt system, not a 120 volt / 240 volt system. Hopefully, there are no 240 volt appliances up there, I see the gas meters, so the water heater, range, and clothes dryer would all be gas (I hope), and the furnace would be gas (I hope), that leaves ... no ac, unless there are plug-in 120v window or through-the-wall units. This 'could be' another problem, but might not be.

The back-fed breaker acting as the main needs to be secured down so it cannot be removed easily or accidentally. That is another problem.

What astounds me, though is that there *are only two (2) circuits* for the upstairs unit. EVERYTHING is operating on those two circuits! That is another problem as you should have two circuits for the kitchen small appliances, and that leaves no circuits for the other outlets.

Also, I don't see a ground bond strap or screw to bond the neutral to ground. That is another problem. Which raises the question: is that enclosure/panelboard even rated to be used as "Service Equipment". If so, it would state so on the label, typically something like 'Suitable for use as Service Equipment'.

Then, of course, there are the other small things shown in the photo.

Then there is that cloth covered wire which looks 'silver' or 'aluminum' but which is likely "tinned copper" - "tinned copper" was used with rubber insulated conductors to keep the copper and rubber insulation from reacting chemically with each other. At this point in time, that rubber insulation is likely dried out, brittle, and of little use. Meaning that the upstairs unit may need a complete new wiring. You will notice that the bottom circuit is newer, with thermoplastic insulation, so ... does that mean the upstairs apartment only had ONE CIRCUIT?

I would recommend having a licensed and competent electrical contractor do a load calculation on the upstairs apartment, re-wiring and adding circuits as necessary. That is your best bet with what is shown in those photos.

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Jerry Peck, Construction / Litigation Consultant
Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )
www.AskCodeMan.com