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-   -   What to do w/ ground wire in older home? (http://www.diychatroom.com/f18/what-do-w-ground-wire-older-home-35678/)

dbldee20 01-11-2009 05:42 PM

What to do w/ ground wire in older home?
 
My house has 2 wires going to each switch & outlet (1 white, 1 black). It is "BX" wire with a steel wrap around it. House was built in 1939. As far as I know the BX wrap serves as the ground & makes that ground when it feeds into outlet/switch box & clamps to the box thru back.

I am putting in a new fan/light in my bathroom. The fan fixture has a ground wire(green) Should I try to connect the green wire to the BX wrap by wrapping it around BX with elect tape or connect it with the white wires that come from the fixture? The fuse panel was changed to breakers recently.

Thanks for any help.

gregzoll 01-11-2009 06:21 PM

It can be connected to the box, but by todays standards, would not serve as a proper ground. If you are able to run new wiring, that would be the better choice.

rgsgww 01-11-2009 07:26 PM

A "bonding strip" must be present to use the jacket as ground.

Is there a thin bare aluminum wire inside the jacket?

dbldee20 01-11-2009 10:07 PM

No there is no bare ground wire inside the BX in my home(it was built in 1939). Just 2 wires.
It is a large exhaust fan/light which doesn't mount to a box, but screws to the floor joists in the ceiling above in the attic after you have cut an opening in the plaster. It would be very difficult to run romex from the subpanel in basement to the attic, and rewire the switches in bathroom. There was already a light where I am mounting the fan. Its above the shower and the original BX is already there and hooked to a switch in bathroom.
An electrician had told me once that the steel sheath or BX armor serves as the ground in older homes where there are only 2 wires. It grounds to the outlet & swithch boxes when it is clamped to it thru the back of box.

Hope this helps.

rgsgww 01-12-2009 07:20 AM

Quote:

Originally Posted by dbldee20 (Post 211306)
No there is no bare ground wire inside the BX in my home(it was built in 1939). Just 2 wires.
It is a large exhaust fan/light which doesn't mount to a box, but screws to the floor joists in the ceiling above in the attic after you have cut an opening in the plaster. It would be very difficult to run romex from the subpanel in basement to the attic, and rewire the switches in bathroom. There was already a light where I am mounting the fan. Its above the shower and the original BX is already there and hooked to a switch in bathroom.
An electrician had told me once that the steel sheath or BX armor serves as the ground in older homes where there are only 2 wires. It grounds to the outlet & swithch boxes when it is clamped to it thru the back of box.

Hope this helps.


A bonding strip is required for you to use the jacket as a ground. If it isn't there, no ground is present.

dbldee20 01-12-2009 08:26 AM

I have checked all the outlets in my home for a ground and everyone of them has a ground present. With the exception of one outlet in basement, they are all 3 prong outlets.

What if I connect the existing BX that powered light in shower to a metal junction box in the attic above fixture (making sure to clamp BX to JB), then run romex from junction box to the fan fixture. Connect the neutral, hot & ground wires from the romex to the fixture and then ground the bare wire from the romex to the junction box? Would this be safe? I could easily mount the junction box to a stud in my attic.

Gigs 01-12-2009 08:28 AM

No bonding strip, no ground. No way around it unless you want to pull a new wire. Since the rest of your house is grounded, why not just replace this one circuit that isn't?

rgsgww 01-12-2009 10:33 AM

Testers will read "ground" doesn't mean its safe, or grounded.

Ex. Bootleg grounds.

If there was a fault, without the bonding strip, the breaker may not trip.

Best to put a gfi on these circuits, but you will not have a ground.

gregzoll 01-12-2009 10:56 AM

I know that mine has the 22-24 gauge Aluminum wire running through. Only remaining BX in my house goes from certain switches to the lights, and the Bathroom is still tied to the bedroom lighting circuit, but will not get updated until we gut it out, along with the Kitchen.

rgsgww 01-12-2009 12:37 PM

Quote:

Originally Posted by gregzoll (Post 211479)
I know that mine has the 22-24 gauge Aluminum wire running through. Only remaining BX in my house goes from certain switches to the lights, and the Bathroom is still tied to the bedroom lighting circuit, but will not get updated until we gut it out, along with the Kitchen.


Whats so bad about that bx? That aluminum wire is the bonding strip. You have a ground present. I would untie that bath and run a ded. 20 though.

gregzoll 01-12-2009 03:12 PM

We need to split the bedroom lighting off to a dedicated circuit, and get the bathroom up to par. You are talking about a 70+ year old house, that originally only had 4 circuits for everything, before the orig. owners needed a Dryer, Washer, and garage.

When we bought it, a new breaker panel was installed at the seller's cost, and from there been splitting circuits etc. I do not mind the fact having BX like the OP, but by todays standards for what you have in a home, it does not suffice.

dbldee20 01-12-2009 05:05 PM

Are you referring to the bonding strip in the panel? If so, yes there is one. So is it ok to secure the ground wire from the fixture to the junction box as I desbribed in earlier post?

dbldee20 01-12-2009 05:24 PM

After a closer look there is a very thin, about the size of a paper clip wire coming out of the BX.

Daltex 01-12-2009 05:35 PM

If it wasn't a bathroom it may not be as big of a deal. Since it is, why not run a new branch (I know it's a pain) with gfi's on the outlets and proper grounding on all. Until you remodel, just use it for the new fan/light and switch. When time to remodel, the jbox is there.

rgsgww 01-12-2009 05:51 PM

Quote:

Originally Posted by dbldee20 (Post 211654)
After a closer look there is a very thin, about the size of a paper clip wire coming out of the BX.


Thats good, you have a ground present. Just ground to box using a ground clip or screw.


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