AskCodeMan

Have an older Square D panel, maybe 20 years old with 62 total circuits in the box. The NEC used to allow no more than 42. Now I am seeing they changed to code to what the panel box is rated for. How would that apply to an inspection done today?

will5443 wrote:Have an older Square D panel, maybe 20 years old with 62 total circuits in the box. The NEC used to allow no more than 42. Now I am seeing they changed to code to what the panel box is rated for. How would that apply to an inspection done today?

That older Square D panel probably has some piggyback breakers it. Provided the piggyback breakers are in their allowed spaces (refer to the schematic as it will show which spaces those are allowed to be in).

New panels are designed and approved to the new code and revised standard, neither of which apply to the older panel.

If you were to install that older panel today (reuse it), it may very well not be approved, but why would you want to reuse an older panel anyway?

The listing and labeling information, which includes the nameplate information and any and all manufacturer's installation instructions, including the schematic and label on the panel, tells the installer - and the inspector - how that particular panel is allowed to be installed ... that is how the inspection should be done, both 'back then' and 'today'.

Jerry probably should have added some pictures. Those are tandem breakers. The best I can tell they are Square D brand. They all go to separate circuits the best I can tell. This was a 4500 square foot home that had been added on to. Whole thing looks wrong to me. Thanks for taking the time to look.

Bill,

I see some piggyback breakers higher up in the panel, and then all those tandem breakers too - looks like way too many breakers (circuits) in that panel, but the only way to know would be the schematic part of the label - that would not only show how many of which type (piggyback or tandem) are permitted, but also where they are permitted to be placed in that panel.

The more important issue that I see which may be presentis all those red conducts - typically that indicates 3-conductor circuits, and 3-conductor circuits typically indicated multiwire-branch circuits, and multiwire-branch circuits need to be connected phase to phase for 240 volts between the conductors (120 volts to neutral) ... and those may be connected to the same breaker - which means the neutral is not serving as a "neutral" for only the differential current between the two legs, the 'neutral' would now carry the full current of both legs and could be overloaded to twice capacity.

Determining if those circuits are multiwire-branch circuit, and determining how they are wired, would take someone poking around in the panel tracing wires and checking voltages.

Determining if any/all/which/how many of those tandem/piggyback breakers are allowed would take finding the schematic and reviewing what it shows being allowed where.

After much research and talking to one of the better electricians down here that I know we came up with the same conclusion that you came up with. Someone's going to have to go in there and remove those wires in order to access the label to see if it's correct or not. According to the electrician is a good chance that it probably is okay. Square D does make panels that can hold a 40+ breakers. Hopefully they will hire my electrician and I'll be able to get an answer once he goes out. In any event thete were a whole host of other problems with the electric that need to be addressed