When somebody is installing breakers initially or doing a major remodel, are there rules or restrictions that must be followed in regard to which breaker goes where in the panel spaces?
Obviously dual-pole breakers need to be installed into a spot where they can reach both phases, and any other instructions on the panel labeling must be adhered to. But beyond that, I'm curious if any of these considerations matter or are stipulated in code:
- Locate largest rated breakers closest to the main, and 15A circuits farthest away.
- Balance (within some threshold) the total breaker ratings on one phase with the other one.
- Balance the expected real-life load on each phase. (Is there even a way to calculate that?)
- In specific locations (e.g. the two separate kitchen countertop receptacle circuits) put these two circuits on different phases — if the circuits are not wired as an MWBC.
- Group standard, AFCI, and DFCI breakers together.
- Group breakers by the rooms they serve, or by circuit type, or by 120/240V, or…
Put another way, if somebody were to pop all of the breakers out of their panel (without unscrewing any of the wire terminals!) and shuffle them all randomly, would they need to apply any sort of code interpretation or common sense to reinstall them correctly?
Best Answer
While we're discussing bad technique, let me hit the awful practice of "Mister Snippy", snipping the wires short so they can only reach the breaker they're on right now (or the neutral bar). Mr. Snippy thinks he's impressing the inspector with wild overinterpretation of NEC 110.12. Actually they're dooming the panel to a bad hair day of wire nut extensions, when changes inevitably need to be made later.
This is a very bad idea for two reasons. First, as Jeff Wheeler discusses, you're dancing with the devil on Stab Limits. I recently saw a panel with a 40/40 quadplex across from a 30... and the OP wanted to change the 30 to a 30/50. If you don't see a problem there, read Jeff Wheeler's answer.
So the idea of crowding the biggest up top, abeam of each other, is a terrible idea.
Second, about three 2-pole double-spaces should be "reserved" if you will, for things that actually have a need to be there -- generator interlocks (particularly "across" interlocks such as Siemens ECSBPK01), surge suppressors, solar, that kind of thing. I'm not saying "don't use them", but anything you put there should be easily moved. A second warning to Mr. Snippy.
The trip value? Pointless. No gain to it. Prioritize other things.
That makes a lot more sense. You just have to think about how houses are being used. You don't run the dishwasher while you're preparing a meal for instance.
Yup, or "saw and dust collector".
Unconstructive and useless. I see it sometimes, but that's just pandering to 110.12, trying to make a panel that looks neat for no good reason.
I think the best question to be asking is, "how do I best facilitate people finding a breaker they're in a hurry to turn off?" That being the reason they have switch throws instead of just reset buttons.