My questions stem from what was supposed to be a simple ceiling fan installation.I am a new owner of a very old house.It was built in 1880.While trying not to do a mickey mouse install,I am searching for ground.Upon removing the existing fixture cover,I discovered a 2 wire system.I have a hanger bar ready to install.The books I am reading are telling me there is ground at the metal box.The power comes from an updated box,but the wiring on the second floor is run through the old knob and tube.The wire casing is not brittle.Is it possible that this system is grounded,and I can attach the ground wire to the metal box?I have a multimeter.How do I check for ground and what should the meter read?Should the knob and tube be eliminated?If so,how do I power up my second floor?Updated wiring was ran up to the attic.How do I test it to know it was properly installed with grounding used?These questions will probably create more,but I have to start somewhere.

 

There is no ground with knob and tube. You could connect a green wire and get back to the panel, but I dont think that will be easy. You are going to have to ignore the grounding to use it on that system.

 

If you just need one grounded outlet (the ceiling fan box is technically an "outlet"), you can do as sberry says and run a grounding wire back to the panel from the outlet. By reading home wiring books, you can learn a number of tricks for doing this without too much damage. It isn't necessarily easy, but it is doable. It is usually almost as easy to run a whole new 12/2 cable from the outlet location to the panel, however, and there are a lot of extra benefits in doing so.

If you anticipate other new needs for your electrical system, you should start thinking about investing in replacing your system with a modern electrical system.

For now, you can simply install the ceiling fan without a grounding connection. This is actually much safer than any of a number of ways you might seek get an improper ground (e.g., using the plumbing, connecting to a grounding rod, bootlegging the neutral).

 

Thanks for the feedback.I did consider installing the ceiling fan and disregarding the ground.I read in one of my wiring books that ground is there to prevent a shock.Considering that the wiring is in amazingly good shape,I feel the likelihood of that is minimal(but you never know).
On another note,I was checking other websites and read that the circuit may be grounded at the box.If someone could confirm that,it would be helpful.Upon checking the box,I found that there were a lot of new ground wires attached to the ground bar.If all these factors are considered,it is possible that I have ground at the location of my planned install.Putting my multimeter leads to a wire and the hanger box,I should see.....what?
I will be out of town for the next week,so I've postponed the install until next weekend(or until I get enough info to feel confident that my work will be safe).I will be back to check the posts and update on how the install went.
Thanks again.

 

I will confirm that your ceiling box is not grounded.

 

Those new ground wires in the panel are likely from new installs. I doubt they grounded the old K&T. I would just install the fan and be done. You are righ abou it being there for shock protection. How does the fan turn on and off? Is it a metal chain? A non-conductive cord would be better, but the likelyhood of you being grounded when coming into contact with the fan is probably minimal. Grounding equipment is really critical when you are near water, or metal sink, or other things that are grounded and you can touch energized equipment at the same time.

 

Thanks for the confirm!!!Will post back with successful install.May take a while,as I discovered hanger bracket is designed for modern 16" on center construction.......go figure.Back to Depotland!!