Has a new panel outside the house made my main house panel a subpanel?

Question

I had a solar system installed. The old 70s main panel never had a master switch to shut all the breakers down. The new outside panel now has a correct 200 Amp breaker. The breaker is labeled Main House Sub Panel.

Here is the problem. While working on the original main house panel (now a subpanel) I noticed the grounds and neutrals are tied together AND it seems some of the grounds go into the neutral bar and vice versa.

I am not an electrician but it seems these are code violations and should have been caught by the solar company that installed the new outdoor main panel. Does it make a difference that the new main panel is outside and technically not in the same building?

Answer 1

Yes, that is a code violation and the solar company should have fixed it, and the inspector should have caught it.

But companies doing these installations are typically on fixed-price contracts. So, for better or worse, they will avoid doing "extra" work. Arguably they should have known that at a minimum they need to remove the neutral-ground bond from the main-now-sub-panel, and when doing that they would have seen the larger problem of ground and neutral wires all mixed up. They either ignored that altogether or took one look and decided they just didn't want to deal with it.

The inspector may have simply ignored it. But it is possible that the inspector thought, perhaps hinted at by the solar installers, that there was originally an outside disconnect/meter main that the installers replaced. If that were the case then the inspector might assume (incorrectly...) that any main-now-sub-panel issues had been handled years ago.

The right thing to do is:

• Make sure there is a proper 4-wire feed from the solar/main panel to the main-now-sub-panel. If there is not (i.e., if they continued using the old 3-wire feed), that is a "call back the solar installers and inspector and complain" situation - do not try to fix that yourself.
• Turn off that new handy 200A breaker and then go through the main-now-sub-panel and remove the neutral/ground bond (if there still is one) and move all grounds to the ground bars and all neutrals to the neutral bars. (Neutrals in ground bar is never allowed, though functionally no different from grounds in neutral bar.)

Answer 2

Not necessarily.

NEC 2020 imposes a requirement for outside disconnects for fireman's use (since pulling a meter off a live building is fraught with arc flash risk). This is in 230.70. Almost always, that disconnect is implemented as a "main breaker" because economies of scale make 200A breakers cheaper than a gnarly Frankenstein tier 200A knife switch.

Obviously by your apprentice electrician's understanding of the code, that first disconnect would become the main breaker and therefore it becomes the service disconnect and thus service equipment: the place where the neutral-ground bond must be, with 4-wire beyond that... right? RIGHT????

Wrong. NEC allowed for that possibility in 230.85. They say basically that if it's there to be an emergency disconnect to satisfy the fireman's rule, it does not need to be the service disconnect for ground establishment purposes. And you can declare it an "EMERGENCY DISCONNECT, NOT SERVICE EQUIPMENT" by labeling it exactly that.

But wait... what if there are breakers there going to other things? Doesn't that make it a regular panel and thus the service equipment? Not necessarily. NEC 230.82 swoops to the rescue, allowing a long list of things to be attached to the supply side (before) the service disconnect. And you betcha, solar is one of them.

So... just like the black tape on a switch loop or the "GFCI Protected" sticker on that kitchen receptacle... there's a fair chance you're only a label short of code compliant.