upgrading with new metered main panel to old 2 wire house questions

Thread Starter


Joined Sep 23, 2013
Here is my situation. I have an old cabin that is wired with the old 2 wire with no ground. The existing main is a 110v 60 amp box with 2 screw in 30 amp fuses making 2 circuits that are fairly equal in load distribution.

It is just a small 1 bedroom, small kitchen, 1 bath, living room cabin. I do not need much to power it and any chance of needing a bunch more later is nil. The existing wire itself is in good condition, but the main box has seen better days and will be replaced with a new metered 220v 100 amp main with 16 breaker slots...more than adequate for any expansion I will ever need.

I want to, eventually, have rewired everything to 12/2 with a ground (in case any outlet at some point needs to be upped to 20 amp), relocate some (most) outlets (replacing all of them with grounded outlets), adding a few new circuits, etc...

Due to finances and time to spend on it I need to do this in stages...so these are my questions. I need power to everything existing as I do this.

1. I intend to start by installing the new metered main first...new #2 wire from the weather head to it, new grounding rod, permitted and to local code, etc. Can I connect the existing 2 30 amp circuits to the new main?

If I can, how do I make that connection (I am assuming, but smart enough to ask first) each hot to a separate 30 amp breaker, each neutral to the neutral bar and the neutral bar in the new box connected to the ground bar?

2. As I add the new circuits and wire them to the new main (and get the chance to add, move, divide the load distribution) I assume I wire them the normal way...is there a problem with "mixed" 2 wire non grounded circuits and the new 12/2 with ground circuits being wired together in the main? (on separate appropriate amp breakers of course)

As I have reached each stage in this I will be disconnecting and removing the old circuits, wire, 2 prong outlets and breakers completely...just not all at once... which is why I ask if it is okay to have them "mixed" for some of that time.

I appreciate your response/advice...


Joined Apr 24, 2011
I assume you will wait for the inspector to sign off on the permitted work before you begin, as what you are planning is a moving code violation itself... though one that ends well. Do make sure that in your local you are legally allowed to do your own wiring. Do understand that your homeowners insurance will not cover that work.

Scary stuff said... my house was built in the late 40's, the service was upgraded in the 80's, and it now has a mixture of 2 wire ungrounded and 3 wire grounded legs.

You should be OK in the end, it sounds like you know enough but also know what you don't know (so you ask).

Good luck!

Thread Starter


Joined Sep 23, 2013
I will indeed have the inspector come out and sign off where the new metered main can be installed (about 2 feet from existing box) and actually it will meet current code as where the old one doesn't in regards to being at least 3 feet from a roof overhang. Does your point of it being a moving code violation require anything of me like a fine/change in how I do it/additional things to consider? Would I be better off installing it in the same place if it is allowed?

On your point of my homeowners insurance not "covering the work"...are you meaning if, say, a future house fire is traced to the electrical being the cause/source they will not cover the loss? If yes, then can only a licensed electrician do the work so it will be covered? And thank you for bringing that point up. And yes I can do the "occupying homeowner" bit to get the permit/inspection done here.

And finally, are my stated "assumptions" of my connections for both the old and new circuits correct?

However your points might just add up to maybe it would be best to have a licensed electrician do this part for me (insurance reasons) and then I can do the rest myself in stages...or for the same insurance reasons have a licensed electrician do that also in stages...Just want to be current, up to code all around, safer, etc...but not at the cost of possibly no coverage.
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Joined Nov 30, 2010
The only point I'm picking up is that 30 amp breakers are not allowed with 12 gauge wire. You have to use 10 gauge wire with 30 amp breakers or 20 amp breakers with 12 gauge wire.