Main Breaker - Miswired connection Question

Question

I am little confused and will be hiring a licensed electrical person to look at it, but wanted to get an idea of what maybe going on or if anyone has any experience seeing this type of issue.

In 2006 the building was converted from a 2 family to a 3 family by a licensed electrician with permits.. The building has 4 Main breakers connected to each electric meter. 1 common main breaker which control all the common lights in the lobby and hallways in the multifamily and seperate main breakers for Apt 1, Apt 2, Apt 3. Each main breaker is connected to a main electric meter. Total 4 electric meters.

Recently I discovered when I wanted to close the main breaker for Apt 2 the lights remained on, only 1 bedroom light went off.

• When I closed the (Common lights) breaker the 2nd apt light went off along with all the lobby lights. While the common lights main breaker was off.

• I turned the 2nd apt main breaker on and all the common lights and 2nd apt lights went on.

• When I leave the lights on in the 2nd apartment and lobby lights and when I close the (Common Lights) main Breaker the electric register on the 2nd apartment electric meter.

• When I close the 2nd apartment main breaker and keep the (Common Lights) main breaker on the electric register on the 3rd apartment electric meter.

• The 1st apt and 3rd apt main breaker have no issues they turn off their apartment lights when I shut then off independently.

• Each apartment has a sub panel.

• the 2nd apt sub panel shuts off the lights.
• However to close the 2nd apt from the main. I have to close the common and 2nd apt main breaker to close the power for 2nd apt.

Thank you again for your help.

Photos of Electrical

Answer 1

There is some confusion reading the question, for example "closing" a breaker normally means turning on the power, the off position is the "open" position.

However I think I get the gist of it, and I think you know what's going on. You have some loads in apartment 2 that are on the house-common service, and some house-common loads that are on apartment 2's service. This happens all the time when houses are divided up, and in my experience it's rarely caught by inspectors.

The landlord is of course obligated to correct the issue. It is a bit of a cost issue, the landlord is paying for some of apartment 2's lights, and apartment 2 is paying some of the common area lighting for the landlord.

It is also a safety issue. Say someone is servicing apartment 2's lights, and they open (turn off) the main breaker for apartment 2, but the light they are working on is on the house-common panel. If they assume power is off, and neglect to verify by testing voltage at the light, they could get zapped.

Answer 2

The fact that either panel can power up the same circuit means there are grave wiring issues present.

It's not unusual when subdividing a house to take a circuit and split it into two circuits, each fed from different panels. You cut the circuit somewhere, and feed the now-dead segment from the other panel somewhere along its length. However, you must be careful not to accidentally backfeed the still-connected segment, because then you will be feeding it from both ends! If the poles are opposite (50/50 chance), you get a Bang! Trip! And you are forced to correct it.

Unfortunately, this important warning sign can be suppressed simply by moving the breaker to the other pole. And now I behold the strange breaker positioning in the commons area panel. Normally I would say "change poles and see if it trips hard", but that option can be kind of house-firey, and now there's a better option: fit a GFCI breaker. With loads turned on, the GFCI will immediately trip if there is a double-fed hot or neutral.

Try a GFCI on every circuit. Not all at once; just buy one GFCI and place each circuit's hot and neutral on it long enough to test. Your commons area panel, while it appears messy with wires, that is a godsend because it has extra length on the wires (particularly neutral) to reach a breaker anywhere in the panel. The "mess" there is not a defect, there's nothing worse than a "neat" panel with all the wires nipped too short to do any further work.

Other defects

That said, the work has some problems.

The gutter (that's the word for it) arrangement is fine. Do you see the ground wire?? It's not so easy to see! The all-metal gutter and metal conduit in/out of it is the ground wire. I have a whole factory wired that way.

Unbest main breaker size. Note how there is aluminum wire (no problem there, aluminum is perfectly fine for feeder) that appears to be 6 AWG. Rule of thumb, that has the same current capacity as #8 copper. There is also copper wire 1 size smaller in that same box, that would be #8. Thanks to 310.15(b)(7) those can be breakered for 50A, so the 40A breakers are needlessly restrictive. Those main breakers are common branch circuit breakers, just bolted down, so it is a $10 breaker.

Bad wire markings. That guy looooves marking wires with electrical tape to change their colors. Don't get me wrong; I'm a fan too. But the red marking is covering up the wire markings so we can't see what wire it is; I usually only mark a couple of inches near the end and where it enters the panel. Also, red vs. black does not matter in a service (unless you're doing janky things like feeding circuits from 2 panels) so it is unnecessary: they can both be black. However, re-marking a wire for neutral is illegal in sizes #6 or smaller, so that spiff tape job he did to mark the neutral is right out and needs to be replaced with actual white wire.

Subpanel grounds. Where's the ground wire to the apartment subpanel? These main panels have a ground connection via the metal conduit, but the onward connections to the apartments appear to be 3-wire cable with no ground. Ground can be retrofitted. Ground does not go to the neutral bar, they must be kept separate at this point.