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Forum Index : Other Stuff : I hate old house wiring....
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Grogster Admin Group  Joined: 31/12/2012 Location: New ZealandPosts: 9060 |
I think most of us who encounter this would agree. Usually presents itself as old fiber-wrapped-rubber-insulated single core, or just plain rubber-wrapped twin or T&E. But from about 1950. BOTH of which, after 50+ years, turn into hard, brittle, crap. They are fine to keep using, so long as you don't DARE disturb them!  If you pull off a light-switch or power-outlet fed from this stuff that has not been moved in years, it turns into DUST with a crackle sound. I did this - I should know better, but....it's a job, and a job is money. Shiet.   Lots of exposed conductors now, and you have to advise the client that this circuit has to remain off-line, till you can re-wire it as it is now electrically unsafe. Most anger is subdued in the client, by running various extension cables, so they still have light and power where they need it. But, damn........why do I even bother to disturb those old connections..... OK, so one light-switch off the wall. Old fiber-wrapped-rubber-core-stuff. Totally crumbling off, conductors now exposed. NO neutral reference. Bugger. LIVE in, LIVE out kind of arrangement. FOR NOW, I fitted a temp switch, and taped it off, so they would have some lights. I was hoping to tap off of this for the new light, but with no neutral reference, I will have to run completely new cables. Probably everywhere on this circuit, to eliminate the ancient stuff. I hate old house wiring. With any new setup, for lights, it would be 1mm T&E(twin-and-earth), and you would feed in and out to every light-switch on that circuit(MCB), providing ALL points with a phase, a neutral AND an earth connection at every switch point. Then, you would use a third cable out at any light switch to the lights on that switch, with the neutral and earth being connected at that switch point. ...and you may not agree with my topology, but that is what works for ME. Rant over. Smoke makes things work. When the smoke gets out, it stops! |
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SimpleSafeName Senior Member  Joined: 28/07/2019 Location: United StatesPosts: 286 |
Ah, the old cloth-covered, nickel-plated, copper wire. Loved it. It's a pain to be sure, but back when I worked as an electrician, we ran across it in old houses fairly frequently. That, and "knob and tube". The spot where they always caused problems was in the ceiling light box. The insulation would simply fall off when you touched it. We fixed it by re-insulating the leads with tape. These days shrink tubing would be a better choice. Tape was an approved method for the time (considering that there were no other options other than re-wiring the house). However, since this was in the late 70's, early 80's timeframe there might be a better option out there now . And yes, both conductors are black. Regardless of what color they started out life as, at this point they are both black. Oh, and did I mention that the joints were all soldered? Great... So to find the "hot" wire, here's how I do it. Standard disclaimer: If you are not electrically inclined, and/or don't understand the risks, hire an electrician. You're on your own here, pilgrim. Option #1 Using a DIGITAL meter, hold one lead in your hand (intentionally touching it), and use the other lead IN THE SAME HAND to do a one-wire voltage probe. With the meter on volts of course. Here in the States, my meter will show from 80 to 100+ volts when I touch the "Hot" wire (the more humid the day, the higher the volts) You folks in New Zealand will get close to 220 volts across the meter, and unless you are doing this with a $5 digital meter you (probably) won't feel a thing. I've always used auto-ranging meters, so a meter with a volts selector rather than auto-ranging is a bit of an unknown. Did I mention to use a good DIGITAL meter while doing this? While your old Simpson 260 would be retro and cool as heck, it would probably tingle a bit as well... And even though it may be "Shorts, flip-flops, and muscle shirts to work day", it would be wise to limit the number of your "unintentional alternate" electrical paths to ground to none. So bundle up! Sketchy? You bet! Does it work? Absolutely! Is it safe? Umm, how does "Two out of three ain't bad" sound? Option #2 Just go out and buy a non-contact tester. They are around $20 at Lowes. Pffft... And yes, Option #1 is how I still do it. And as recently as about a month ago (I'm mentoring a Mechanical Engineer in the darks arts, and it seemed appropriate). Ona personal note, I apologize for having been gone for so long. I had a triple bypass in October, and then caught COVID in February. I am better-ish now, but not great. |
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| Godoh Guru  Joined: 26/09/2020 Location: AustraliaPosts: 378 |
I go along with you Grogster. I am a retired electrician in Oz. I used to inspect the switchboard or the roof cavity first if there was VIR (vulcanised indian rubber) or any really old wiring there. Then I would tell the customer how old the wiring was and suggest it was replaced. I would not connect anything to a VIR or rubber coated cable. I thought it better to lose the job than to do dangerous work. I even came across a house wired in lead sheathed rubber cable once. I have no idea when that stuff was used but I suspect maybe it came from the Arc when it was scrapped. As for using 1mm t+E for lighting, that assumes that there is no insulation in the ceiling or you are using a 6 amp circuit breaker. I always used 1.5mm t+e and a 10 amp breaker here. I am very glad to be retired, as the standards writers seem to take great glee in writing new standards and making them difficult to interpret. Cheers Pete |
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TassyJim Guru Joined: 07/08/2011 Location: AustraliaPosts: 5900 |
I never really had to bother with anything below 11kV during my working life but during my trade and for many of the small house jobs I did do, there was split conduit to deal with as well as the rubber falling off. Trying to break into steel split conduit to add an new point was fun, especially in a hot Queensland ceiling. At least we didn't have ceiling insulation to deal with. Now the big issue is wiring car chargers in the garage. Customers wanting 32 amp circuits in the garage at the other end of the house to the underrated switchboard. I cheated and limited my charger to 13 amps to save wasteful voltage drop. The car is still fully charged by the early hours. Jim VK7JH MMedit MMBasic Help |
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