Well helping out a friend with an old house batroom remodel when we went to upgrade old outlets with cloth type wiring, FIRST question how do you establish which leg is hot and which one is neutral? They both appear to be the same with exeption of one being a bit smaller in diameter than the other. SECOND question how can I connect a GFI receptecal to this wiring.

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thought of another question , on this bathroom we add an exhaust fan runs through wall and have it on a switch. After reading some post I am thinking this should be GFI protected since it is reachable from the shower, someone might lean out to turn it on and get shocked. Is this what GFI are to protect from wet areas?

Thanks Monty

 

When you say cloth wiring, that could mean one of two things - which are each totally different animals:

1) Is it sheathed cable, with 2 or 3 wires inside a jacket, and each conductor is cloth-wrapped? (Like an older version of Romex). Does it contain a ground?

2) Is it 2 separate wires, possibly leaving the junction box through two separate holes? This would be knob and tube, and a project that you want to be real careful with as wiring this old may be brittle and dangerous as-is.

You need to go by the manufacturer's instructions. Most exhaust fans do not need GFI protection if they are not within the shower/bath enclosure. The switch is plastic anyway, and doesn't pose much of a shock hazard. Now, if it were me, I'd probably want to move the switch a bit away from the shower, or at least try not to touch it while dripping wet... something my Mom taught me a long time ago.

 

By code you really can't do much with K&T (knob and tube) if that is what it is but change out fixtures. You can't extend it by adding newer wire.With lights you have to be careful because many require wire with a higher insulation temperature rating then K&T.

From what I understand you can use a non-contact tester (tick tester) to find the hot. My way is to either run a grounded extension cord from a receptacle with a known ground or a wire from a good ground such as a metal water pipe and measure for voltage between ground and each wire. You will get 120v to the hot wire.

 

Here is more detailed informatioin on wire and our plans.

The wire is two seperate legs wrapped with black cloth like insulation with no ground present.

The house had an electrical upgade a few years back and a GFI was install in this bathroom but when we use one of those testers you plug in to test GFI only the middle yellow light comes on and means "open Ground" and when we try and use the trip button on the tester then the red light comes on, but the tester does not have an interuptation for red only.

Now what we did is from the top side of this GFI ran #12 to a switch to a bathroom exhaust fan. It all works well but we have concerns about the switch because 1. to close to shower (3' or so) 2. we ran metal type wire mold, the walls are un-fishable, they are old plaster type.

Again every thing works well just need to know how to make it as safe as possible.

 

You can not by code extend an ungrounded circuit. You can not by code extend a K&T circuit. There are therefore two code violations in what you did. The correct way to do this is run new cable from the breaker or fuse box to the GFCI and go from there.

 

Thanks Ray, now to figure out a way to get a route to the panel box from upstairs...ugghhh

 

Do you have a crawl space or basement or is the receptacle on an outside wall? If any of these three you can run conduit on the outside of the house to get there. With the first two you'd just run from panel to basement or crawl space. For the last you would run around the house and into the wall.

 

Depending on the age of the house it may be easier than you think to fish into the walls. Just measure carefully to see if the walls are stacked on top of each other.

A string and a short piece of chain dropped into a hole in the wall can help you pull the wires into the walls. Plaster can be patched even if you need to cut out a section and replace it with drywall.