I just moved into an older house that was built in 1941 and have gone through multiple renovations over the years. It has three separate panels.

The meter is on the outside wall of the garage, and next to the meter are two panels which I labeled "A" and "B".





Panel A - has the main breakers to turn off EVERYTHING in the house. It is labeled "MAIN 1 OF 2" with a Sharpie. It controls the wiring in the two original bedrooms and bathrooms, as well as the downstairs central AC handler and compressor.

Panel B - controls the outside wiring, the pool pump, spa heater, pool lights, outside motion lights, pond pump, post lights, front gate motor.

Then inside the garage I have another panel, which I have labeled "C".



Panel C - controls the kitchen, garage, living room, dining room, second floor addition.

I am thinking panel A is the first and original panel? Then panel B was added and then the panel C inside? So panel A is the "main" panel and B & C are subpanels?

As I try to determine which breaker controls what, I need to label each of them so I know what breaker controls a particular receptacle or switch...I make a notation on the back side of the cover plate that this is circuit 8A, this is circuits 5B/7A etc, but with three panels I need to reference which panel. Is there a customary convention to follow for labeling the panel+circuit? Is it something like A,B,C or I,II,III or something else?

 

If turning off panel A or breakers in panel A makes panel B and C go off, then you are correct they are sub panels.

 

Panel A looks to be the main panel.
Panel B is fed from Panel A.
It looks like panel C (which is a sub panel) is powered from Panel A.

Beautiful picture of panel C. Panel A needs a closeup pic too.

 

Here are closer pictures of Panel A.





What would be a good way to label at the fixture end which panel it comes from on top of what circuit they are on?

 

Those two splices (greenish) are the tap/supply to panel B. So panel B is protected by the breaker on the left of that panel.

Label them with panel and circuit.
C-1,3 (240v)
C-2,4 (240v)
A-1
A-2
etc..

 

OK sounds good.

If I label them say:

C-1,3 (240v)
C-2,4 (240v)

could it easily confuse someone else to think "C" just mean "Circuit" and they turn off the wrong panel not knowing there are others? Would I II III or 1 2 3 be better? Or PA, PB, PC be better?

Are those green taps typical? I have seen subpanels have a large breaker in the main panel and wires from that breaker runs to the sub.

 

I just walked around the factory I am in. Panels are marked LP for Lighting Panel, and CP, and a few more. BUT, you are talking about a simple install with only 3 panels. I'd do what Pete suggests, and make sure the exterior of each panel is marked with the A, B, or C. Are you marking each recept on the inside of each cover plate? I just did that, from recommendations from this board.
Yeah, that smaller tap wire, if not 3/0, is not going to be rated for 200A. Not sure about rules on very short feeders, but I saw that also.

 

Are you sure? I only see one 2-pole breaker and one 1-pole breaker for branch circuits. Is there another subpanel fed by Panel B. The only other breaker I see in Panel B appears to be a backfed 2-pole main breaker.

 

You are correct I had messed up there. The pool pump were powered from Panel A. Panel B is only for the DP 60A spa heater and another 20A which does all the outside motion lights, pole lights, some landscape lights and a small pond pump etc...



Is Panel B even necessary? Can these be added to Panel A somehow?

 

Panel A looks full. I don't see any empty slots. That is probably why they added panel B.