I'm in the process of attempting to perform some cleanup in this panel and also reconfiguring and adding several new circuits. This panel is a vintage Westinghouse/Bryant Electric 100 amp main service panel of unknown date, Catalog No. B20-20 FN, SN, with 20 circuit capacity. Again, I'm performing cleanup, but as you'll note, the neutrals and grounds are all grouped together on the right side of the panel are are pretty well maxed out, with no room to add neutrals and/or grounds.

That stated, my question pertains to adding an additional ground bar in this vintage panel. There are 3 sets of predrilled holes in the upper left section of the panel, but I can't locate a new ground bar with hole spacing that will line up with these existing holes. Therefore, I'm wondering if I can simply drill and tap two new holes in the bottom section of the case and install a new Eaton ground bar in that location, and then connect the new ground bar to the existing bar with #4 AWG ground wire?

Existing Westinghouse Main Service Panel - Vintage

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  • Is there a printed diagram/instructions anywhere - perhaps on the inside of the panel cover? Many panels allow 2 or even 3 grounds (not neutrals) per ground screw, and that information would be in that diagram. Jan 4, 2023 at 18:26
  • @manassehkatz-Moving2Codidact There is a label with diagram on the panel cover, but it isn't overly legible. However, it does contain a diagram which depicts the neutral bus bar and ground bar configuration that's currently in the panel, but it doesn't seem to contain anything else that's more descriptive
    – Craig
    Jan 4, 2023 at 19:47
  • The picture lists ground bars in the Accessories. Hard to read. If you took the panel cover to a supply house that sells Eaton BR products, they should be able to figure it out. Don't go to Home Depot/Lowes/etc. - they may have the correct product but you can't count on finding someone knowledgeable enough to know what is really the correct product. Jan 4, 2023 at 20:18
  • Actually, I contacted Eaton directly and their response was "Unfortunately our product line has not tested the present ground bar kits on old Westinghouse or Bryant panels and cannot confirm if mounting holes would match as well". I did verify that there aren't any Eaton ground bars that will match up with the existing pre-drilled holes in my panel. Therefore, I was thinking that I'd grab a new Eaton bar drill/tap (2) new holes, sand the paint off the panel, install the new ground bar and then bond it to the existing ground bar. I was just wondering if anyone thought that this was a bad idea.
    – Craig
    Jan 4, 2023 at 20:29
  • 1
    Your idea is actually pretty reasonable. That being said, I suspect an Eaton dealer who has been around for many years would likely know exactly what works and what to do. Jan 4, 2023 at 20:51

1 Answer 1


Given that you already want to clean up, reconfigure, and add several new circuits, and that it looks like there are a few "alien" (incorrect type) breakers already in the panel.. and given that this panel is installed out in the open, with every connection going to flexible cables..

My suggestion is: goodness no, don't put US$50 of parts and all that time and effort into this panel. Spend US$400 on parts and a bit more effort to install a new panel with 30-40 spaces instead. A 125 amp panel would suffice, but if you go for a 200 amp panel instead, it'll be all set for some future day when somebody decides to upgrade that feeder wire for more capacity.

That said, yes, I believe you could install a new ground bar as you described. If it's mounted with 8-32 or 10-32 screws there should be enough thread engagement (1-1/2 turns, I think is the rule?) that the 4 ga jumper wire would be unnecessary. The jumper wouldn't hurt, though.

  • I would love to remove the panel in it's entirety and install a new panel and breakers. However, I wasn't sure if doing so would be beyond my skill set. I'm willing to attempt anything (which is sometimes stupid), but I honestly don't know how to disconnect and reconnect the main service conductors.
    – Craig
    Jan 4, 2023 at 20:34
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    Yeah, the main service conductors are the really tricky part. Not complicated but dangerous. The right way to do that is to have power company pull the meter, then you replace the main panel (get one with a main breaker, not backfeed like this one, and get a lot more spaces) and once the main breaker is in they put the meter back in. The catch though is that (a) many places won't let a homeowner do that, and inspection is almost always required (for good reason) and the power company and local jurisdiction will likely say you now get 200A service and need a bigger service feed Jan 4, 2023 at 20:55
  • and possibly redo the ground rods, etc. etc. etc. (Though all easier than what I went through - at least you already have breakers - I had 2 fuse boxes + 1 small breaker panel - it was a lot of work.) Jan 4, 2023 at 20:55
  • @Craig This looks like a subpanel fed from elsewhere. If there's a service disconnect upstream from here which is in your control -- a circuit breaker in the same box with your meter outside, for example -- then the feeder conductors that bring power into this panel are handled just like any of the branch circuit conductors. De-energize the whole panel, route conductor to the appropriate terminal, use a torque wrench to tighten the terminal to spec. This is an all-day project but if you have the ability to shut off the power then it's doable.
    – Greg Hill
    Jan 4, 2023 at 20:57
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    Another idea: do you have space to add a new panel next to the current one? If so, you could 1) get a large panel and install it as a subpanel to run your new circuits, 2) move over circuits from the old panel at your leisure, then 3) have a "swap day" where the power company pulls the meter, you (or an electrican) install the service wires and a neutral-ground bond in the new panel, abandoning the old panel, and the power company reinstalls the meter. This would get you started on the new panel solution today without committing yourelf to finishing it now alongside the kitchen remodel.
    – maples
    Jan 5, 2023 at 1:50

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