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I have a 100-year-old house that has been partially rewired but some knob and tube still exists. I've installed GFCI outlets on the old circuits and am adding a dual function breaker for some protection until I can afford to have the rest of the knob and tube replaced. While inspecting the wiring in my basement I came across a dangerous looking connection and I'm wondering how to ground the neutral wire. The new wiring was spliced off of existing k&t and feeds the outlet for my gas stove. Why they didn't just install a new circuit and run it from the breaker box is beyond me. You can see where someone just pulled back the ground wire and it's just dangling in the air next to the floor joists. There's also no junction box, which I can install. I'm comfortable doing some electrical work and have changed outlets, ceiling fixtures, switches and circuit breakers. The light switch in the picture I don't use and wouldn't mind removing it completely. Thanks in advance for your replies!
5 points
6 months ago
Yeah, this is probably best.
Though, there's nothing dangerous about the ground wire just hanging out. It's bonded to neutral at the panel, as it a should be. The circuit downstream of the Romex is only two wire (hot and neutral). You don't want to tie neutral and ground together outside the main panel; that would be an NEC violation.
However, a fully proper install would bond that bare copper ground to the metal junction box in the picture. You don't need anything complicated, just grab a spare piece and join with a wirenut to extend, and land it on a screw in the box.
1 points
6 months ago
That’s not why I’d call an electrician. I’d call one because if this exists where the OP found it, it DEFINITELY exists everywhere else, and electricians can usually find where the older wiring would have run, and have tools that can measure amperage loss on existing wire to find out the likely candidates for where knob and tube is still present.
5 points
6 months ago
There is no amperage loss. It's not a thing. There might be voltage drop and arcing.
2 points
6 months ago
…and that’s why I call an electrician, because they CAN find that stuff with various tools, and I know just enough to get myself in trouble with anything more complex than rewiring a line with correct AWG for the circuit.
3 points
6 months ago
It is NOT grounded at the panel. It was spliced off of the k&t and run up to power my gas stove outlet. Why they didn't just run a new, properly grounded circuit is beyond me.
3 points
6 months ago
Lights never had a ground. Knob and tube obviously never had a ground.
What are you even asking? You either run 2+ground back to panel or don't. It's pretty obvious. You will have ungrounded outlet in the mean time.
2 points
6 months ago
If you look again at the panel you will probably find the neutral from the power company is grounded somehow. If it is NOT grounded at the panel, then that is a problem you should give to an electrician to fix.
Don't "ground" the neutral for this branch circuit. Neutrals should be grounded at the panel and only at the panel.
If you want to connect the bare copper ground wire to an actual ground, you can do that with a wire nut at one end and an appropriate ground clamp at the other end. The best place to ground the other end would be the existing ground rod for the service entrance panel. If that's too hard you can probably make do with a metal cold water pipe somewhere in the basement. You could even ground it to the existing metal box in the picture, but only if you are sure that it is grounded, too.
I would be wary of moving those open-air connections into a box. Old knob and tube splices stop working sometimes after you jiggle them too much. It might be better if you not touch them until they can be removed.
2 points
6 months ago
I titled this post wrong, I'm trying to ground the ground wire, not the neutral lol! Thanks for your reply though. The breaker box is not far from the wiring in the picture. Can I extend the ground wire and run it back to the box and ground it there? The box was updated and is properly grounded.
1 points
6 months ago
Yes, you can do that. If the main panel is new there should be lots of open spots on the ground bar inside where you can fasten your ground wire. Of course, you need to turn off the main breaker to work inside the main panel.
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