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1960s House Wiring No Ground Wire

Posted by dmack (My Page) on
Wed, Oct 13, 10 at 15:59

Need some advice on this. I am replacing a over the oven vent/light hood with a microwave/vent that has a grounded plug. The wires that are connected to the hood go into a junction box. Two seprate wires from the hood each have white, black and ground one set went from the hood fan and the other went to the hood light. They both went into the junction box where the grounds were tied together. The old house wire with no ground wire went from a wall switch to the junction box and the black was wire to the blacks and whites to whites but no ground from old wire. Question is can I get rid of junction box and run old wire directly to a new outlet box and operate microwave safely?

Thanks in advance for any help with this,

DMack


Follow-Up Postings:

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RE: 1960s House Wiring No Ground Wire

Even if you could do this in your jurisdiction(which I doubt), my advice is pull in a new circuit. The wiring in that house was not designed to add a microwave where the old hood fan was. I can almost guarantee that the hood fan is on with many other things, including probably the dishwasher(if so equipped) the refrigerator, counter receptacles and the bedroom lights and that chest freezer in the garage. Really, I mean it. Pull in a new wire.


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RE: 1960s House Wiring No Ground Wire

Thanks for the advice. I checked out the fuse box and cannot even find the grounding wire to the box. Looks like I will ground out fuse box first and then run a grounding wire from cold water pipe in attic to outlet box. The main line from the switch is going to another light switch and looks like it runs down to fuse box.

Thanks again,

DMack


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RE: 1960s House Wiring No Ground Wire

Pull a new 20a circut from the panel. I've seen kithcen circuts where everything is on the one fuse- and i'm 14.
if you ever replace the panel, use squared qo-easy to use, lasts forever. also good quality. i hate my ge panel.


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RE: 1960s House Wiring No Ground Wire

Don't do any of that! You are REQUIRED to run a new 20 amp circuit from the microwave to the fuse box. The box is already grounded by the neutral wire from the electric service. It should however also have a grounding electrode wire to the main water pipe. Even if the outlet didn't have to have a new circuit ran, you can not just run a random ground wire up to a water pipe in the attic! The only grounding connection allowed to the water pipe is the electrode conductor from the panel connected to within 5 feet of where it enters the house. You also can not run a separate ground wire back to the panel from the outlet, the ground has to be in the same cable that feeds the outlet.

If you don't have an extra fuse, which is likely, this is going to bring the need for a service upgrade.


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RE: 1960s House Wiring No Ground Wire

Umm, either the OP didn't read, or didn't understand my post. Adding a ground wire will not help you here. I said to pull in a new CIRCUIT. you don't have the capacity on that circuit for a M/W. See my post again about the myriad items on a typical circuit in a house of that vintage. New circuit. NEW. CIRCUIT.


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RE: 1960s House Wiring No Ground Wire

Thanks for everyones advice. What has me concerned is there is no ground to the main water pipe. Decided to leave this to a professional and upgrade to circut breakers and have a dedicated circut for microwave.

DMack


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RE: 1960s House Wiring No Ground Wire

The water pipe may not be the ground in this case. However, if your house water piping is metal, it should be bonded to the house ground. This is to protect against the piping if it were to become electrified rather than providing a ground for other things.

You should point that out to the electrician when he comes as well.


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RE: 1960s House Wiring No Ground Wire

The ground in the fuse box is the neutral running back to the power co. transformer. Neutral and ground from the first fuse box to the pole is the same wire, any subpanels after the main fuse box needs to have a seperare wire for ground and neutral.


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RE: 1960s House Wiring No Ground Wire

It also is connected to the building grounding electrode system.


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RE: 1960s House Wiring No Ground Wire

you misread my post, spencer electrician. i was reffering to replacing the panel inthe future and trying to reccomend the panel i liked best, and lasted the longest-my neighbor's has been in service for over 50 years!!!


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RE: 1960s House Wiring No Ground Wire

I don't think I saw your post at the time, posted 2 minutes after yours. Probably was typing while your post went out. All my comments were directed to the original poster's situation, nothing that you said.


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RE: 1960s House Wiring No Ground Wire

I've installed several GE panels. I like QO better, but the GEs are OK. I've gotten to kind of like the goofy way their half-width double pole breakers fit. Just make sure you get a copper bus.


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RE: 1960s House Wiring No Ground Wire

ge panels belong in the scrapyard, not anyone's home or anywhere for that matter.


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RE: 1960s House Wiring No Ground Wire

what if the neutral wire from a receiptical is jumpered to the grounding prong on the outlet,...after all that is whats in the first sub panel? or is this a code that prevents this method of wiring? if a hazard, please explain in reciting a code from the NEC BOOK please


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RE: 1960s House Wiring No Ground Wire

Please start a new thread with your question.


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RE: 1960s House Wiring No Ground Wire

It's a hazard and so blatantly wrong, that if you're even considering it you have no business even taking coverplates off.

250.130 would be a good place to start but it's probably in violation of a ton of other articles as well. About the only time you can use the grounded conductor to carry the equipment ground is a few grandfathered cases for stoves and electric clothes dryers.


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RE: 1960s House Wiring No Ground Wire

david - that is called a bootleg ground and is a really bad idea. often it is done by unscrupulous house flippers.


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RE: 1960s House Wiring No Ground Wire

A bootleg ground would be connection to another circuit's ground. This one is just plain wrong.


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RE: 1960s House Wiring No Ground Wire

"A bootleg ground would be connection to another circuit's ground"

It is also commonly used to refer to using the neutral to supply a connection to the ground of a receptacle.


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RE: 1960s House Wiring No Ground Wire

Smithy123: I have to disagree with your statement regarding GE panels. I use nothing but GE Powermark Gold and they have been great with proven track records....these have a copper bus, METAL mounting rail and are American made...your Square D's have plastic mounting rails, are made in Mexico and in some cases have an aluminum bus....that is garbage, not the GE's.


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RE: 1960s House Wiring No Ground Wire

Scott: don't get him started.


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RE: 1960s House Wiring No Ground Wire

Luckily Smithy123 has been gone for a l-o-n-g time!
His advice was usually wrong anyway!


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