replacing fixtures/ knob and tube

[hillbillyjake]

I'm needing an opinion, I am a novice at wiring. I've replaced outlets, switches, and fixtures in our home. I've also help a buddy of mine, who is a licensed electrician, when I added an addition to my home. My parents have a home, pre-1950's?, they need outlets, switches and some fixtures replaced. Their wiring is knob and tube. They are elderly and on a limited budget. Can I or should I, attempt these replacements?

[pushkins]

Yes you can change out the switches and outlets, pretty much the same as NM cable BUT be careful to not cause damage to the sheathing on the cables, it's usually very brittle. If you do expose any wire make sure you wrap it well with a good quality insulation tape. Obviously there will be no ground to connect to the new switches and outlets, unless someone ran one at a later stage.

[HayZee518]

unless you are priviledged to have a real old electrical supply house near you, you're not going to find any more two prong outlets and you can't replace the old ones with the three wire grounding type. you can replace the old outlets with ground fault receptacles. yes, they have a third hole on them but the outlet is electronically measuring the imbalance between current going into a device and current coming out of the device. knob n tube wiring is 14 or 12 gauge tinned copper wire. the insulation type is rubber with a jute fiber wrap. exposure to heat and generally old age makes the rubber brittle. the jute fiber will just fall apart. like pushkins said please insulate questionable wires with a good rubber insulation or plastic tape.

[hillbillyjake]

Thanks for your advise guys, probably will also use a tester to figure out hot and neutral. Once again, thanks!

[HayZee518]

to figure out hot and neutral on a knob and tube circuit, its easy with a standard neon tester. make sure you aren't grounded anywhere! grab one of the prods with your thumb and forefinger with one hand. touch the other prod to a bare wire. if it is the hot, one of the elements inside the neon tube will dimly light. look carefully you can see it plain as day but it will be dim. touch the prod to the other bare wire. a neutral will NOT make the neon tube glow.