Background: - House built 1979. Two panels in the unfinished garage (Murray plug in panels). Both are mains with what looks like 200 amp service to both (they both have feeds from the outside coming into the panel, both have a bonded neutral/ground bar, when I flip the service disconnect on the left panel, the right panel is still hot and vice versa etc). Panel on the left is the “big boy” panel for electric range (no longer used), electric furnace (no longer used), AC and some 240 circuits for my table saw, dust collector etc. Right panel handles basically everything inside the house and the garage other than the big boy circuits. Meter and utility box just on the other side on the outside wall. Haven’t been able to open up the utility box yet (painted shut) but will. I’m assuming I will find the master cutoff (or in my case perhaps two).
The right panel has no main service disconnect as the left panel does. Instead, it relies on what I understand to be the now defunct “6 throw” rule. The top part of the panel is always hot unless I were to throw the master cutoff and service to the bottom part can be disconnected with the 60 amp double pole breaker on the right. As you can see, the original wiring made ample use of MWBCs and several tandem single pole breakers (the ones on the left are both MWBCs and no breaker ties). There are no open breaker slots on the bottom of he panel and 2 each right/left on top (presumably because of the 6 throw rule. The face plate of the right panel clearly labels that upper section as “service disconnects”).
I was thinking about upgrading some of the breakers in the right panel to accommodate some AFCI/GFCI but now I’m rethinking/questioning this. Specifically what I was thinking about doing was getting rid of the two tandems on the left and replacing with double pole breakers (retaining the MWBC). I can’t find a combo AFCI/GFCI double pole breaker and one of those is for the washing machine so I would just go AFCI breakers and throw a GFCI receptacle on the washing machine outlet.
Initially I was thinking that I would move one of the tandems up top and soak up the two open slots on the left with the double pole (which would then leave room for the other double pole where the two existing tandems are) but then I realized I would run afoul of the 6 throw rule (which doesn’t exist anymore regardless from what I’ve read). That means that I’m stuck (I think…). Siemens now makes a single pole tandem AFCI breaker but it’s really not designed for a MWBC that I can see because I’m not seeing anything about a common trip and I’m not big on breaker ties if they can be avoided.
There are other problems in the panel but some are fairly easy to solve (i.e. replace some of the single pole (non-tandem) MWBCs with a double pole). In fact, I threw both legs (two breakers) on one of the MWBC’s yesterday and my voltage tester was still going nuts on a circuit receptacle and for the life of me couldn’t figure out what was going one so reflipped the breaker and all was well (which very likely indicates I’ve got a sketchy breaker).
Is it possible just to replace the “inside” of a panel (i.e. the hot bar that runs down the middle the breakers attach to) and add a master disconnect at the top. While I realize that even with a master disconnect the service lines coming in are still hot (unless the master cutoff is thrown), I’m not super thrilled being around a panel where about 1/3 of it is always hot. Hard for me to tell from my panel how it’s constructed (i.e. can the middle part just come out) and I’ve been looking at pics of new panels but can’t tell either. Obviously a major project but if possible seems far less work than replacing the entire panel. This also seems like potentially less work that moving some of the circuits in question over to the other panel. This question is about addressing the problem noted above but also peace of mind.
Irrespective of first question, are there any other alternatives to my dilemma on the two tandems on the left (other than moving over to the other panel)? The tandem on the right side is fine btw in the sense that it’s not a MWBC but still lacks a breaker tie. Maybe there is a tandem single pole breaker with a built-in switch tie or a common trip that I haven’t been able to locate?
Some of this work could get complicated and I would get a pro in but I like to understand what I’m dealing with regardless.
I’ve read lots of stuff on Stack which has been very helpful (and have scoured everything I could find on this topic). This is my first post and apologies for the length and probably stupid questions but wanted to be as detailed as possible. And "you're chasing your tail" is perfectly welcome