You don't know what you have! You already have the best wiring method made. 90% of my brand new work is exactly this stuff, and it's required in industrial installations.
We just need to get you up to speed on the stuff, so you can hold your head proud.
Also if you rewire your house, you'll need to come up to all the current codes, which will mean AFCI and GFCI everywhere.
The rules for grounding devices to metal boxes.
- If the device is not a receptacle, and has a metal yoke, it will automagically pick up ground via the mounting screws.
- If the receptacle is marked "Self-Grounding" on a stamp somewhere (usually on the yoke), then it will pick up ground via a wiper that touches the mounting screws.
- If the receptacle's metal yoke has clean hard flush metal contact with the box flange, that grounds it.
The only case you have to worry about is a) it is a receptacle, b) it is NOT marked self-grounding, and c) it is held above the metal box by its drywall ears (or contaminants or crud are in the way). In that case you need a ground jumper to the metal box.
You can cause any metal box to have a ground "wire"
- In the back of the box is probably a hole already tapped for a #10-32 screw.
- You may use a "ground clip" to attach to the side of the metal box.
- You can drill your own #10-32 hole, and even get special self-drilling screws.
Let's get you up to speed on what you have
The problem I've run into is that the house was built in 1960 and the electrical system as a whole is grounded via the conduit
Yes. This is the best system made. Even today. In fact when you get into commercial/industrial, Romex isn't allowed and you MUST build that way. Chicagoland also requires this. It is a better system.
I've done live testing of the grounding capacity of 60 year old conduit in a condensing environment, and it definitely works.
Most components I've been purchasing require a ground wire. I've added a few pigtail grounds to the electrical boxes and that seems to have worked out fine.
Well, that's how you do that, and that's fine.
Per NEC 110.2, all equipment installed must be UL Listed or equivalent from ETL or CSA. You cannot use random Chinese garbage bought mail order because it is unsafe, but also won't have competent instructions. Competent instructions ought to provide for metal-box installations, since there are a lot of metal boxes in North America.
Even if the wiring is Romex, the Romex must be grounded to the metal box first, and then most things can pick up ground automagically as discussed above.
If a receptacle can't ground by hard-flush metal contact, install a "Self-Grounding" receptacle and let it pick up ground off the screws. These are the $3 ones that come in their own box instead of loose in a bin. They are better made, also.
As discussed above, almost everything will self-ground via its metal yoke, and any ground pigtails are simply superfluous and can be left to dangle.
If you have kit with a plastic yoke, then first make sure it is actually UL listed (and if not send it back). Then you'll have to use a ground screw or ground clip.
In rare cases, you have smart switches with BOTH a bare AND a green wire. Follow those instructions CAREFULLY but the green wire is functionally neutral, but they have gotten UL approval to bootleg neutral off ground for that switch alone. In that case either a) since you are in conduit, just pull a real neutral wire! Or b) ground it to the box.
I have a licensed electrician (also a friend) that is going to replace the old, recalled circuit breaker panel
Do you want a second opinion on whether that's even necessary? Zinsco and FPE -> replace, otherwise you can probably flip it and make it a subpanel of a new main panel, and save yourself a world of wiring lol.
What's far more helpful to DIYers is having a "Meter-Main" so you can fully de-energize the main panel. (well master panel as the "main" is now at the meter).
However, I'm seriously starting to consider gradually rewiring the house.
What I'm considering is using the existing wiring as a wire pull to replace it with up to code Romex.
Is this even worth doing or is it a foolish ambition?
I would say it's ... under-informed, but we'll fix that right now.
Does wire get old and rotten? Sure. It can. You inspect it. If you don't like what you see, wire is cheap.
However you seem to have a misconception that Romex is better than 62-year old TW wire. That would be "a bit of a horse race"... if the conduit has water ingress it's no contest, the Romex loses.
Anyway, no more TW for you. You'll use the new good stuff, dual-rated THHN and THWN-2.
- T = thermoplastic
- H and HH = "high heat" (your only limit is the thermal rating of the terminals, and 240.4(D) as usual).
- W = wet rated
- N = nylon outer shell for easy pulling
- -2 = 2nd revision of THWN raising its thermal rating to match THHN
Yeah, you can use the old wires to pull in the new wires, just try to do all the wires in the conduit at the same time (this will go FAR easier). Note that it's common for some wires to pass through a box on their way to somewhere else, you'll want to preserve that, because if you cut and splice you need to add more than a 12" loop to do that splicing, and it will add cubic inch fill to the box.
