Another 2 prong electrical question

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  #1  
Old 10-18-15, 01:42 PM
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Another 2 prong electrical question

Greetings all,

Sorry if this subject is beat to the death, but I am another one of those "halp me 2 prong plugs" people.

My understanding is that to properly go from 2 prong to 3 prong, I need to either run new wiring, or use GFCI with a "no equipment ground" sticker. I just want to make sure I don't have an option 3 I'm not aware of. I've seen a clip that hooks to the metal box, but I'm under the impression those won't cut it.

Thanks for the help. I've been doing a lot of reading on electrical lately and find it to be quite interesting.

Cheers
 
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  #2  
Old 10-18-15, 01:46 PM
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You would need to determine what type of cabling your house uses for a third option.

If it is two wire NM (romex) with no ground.... no third option.
If it is BX (metal clad) cable with the internal bare ground wire then you can add a jumper wire from the box to the device.

If you do have the BX.... go to where it's connected at the panel. Look outside where it goes into a connector. Do you see a little silver wire wrapped around the metal armor ?
 
  #3  
Old 10-18-15, 02:54 PM
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I"ll take a look right now. I'm working the basement at the panel turning things on and off while we replace some switches.
 
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Old 10-18-15, 03:10 PM
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If you have older NM cable look in the breaker box for a bunch of small (#16) bare wires going to the neutral bar.
 
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Old 10-18-15, 04:56 PM
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I didn't see anything that looked like BX running back to the breaker box. It's definitely older cable (1900s house) and I haven't found anything that looks like ground conductor with any of the switches so far.
 
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Old 10-18-15, 05:04 PM
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It's definitely older cable (1900s house) and I haven't found anything that looks like ground conductor with any of the switches
If it is what I described in my post you won't see grounds except in the breaker box.
 
  #7  
Old 10-18-15, 05:10 PM
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interesting! I am done for today but ill try and take a look asap. Any good info on that type of wiring?
 
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Old 10-18-15, 06:48 PM
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You do have another option. You can run a separate ground wire from the receptacle in question to the panel with the breaker for that branch circuit. The separate ground wire may follow the circuit conductors exactly, approximately, or vaguely. Should this separate ground wire first reach a fat ground wire (grounding electrode conductor) leaving the panel for a ground rod or water pipe, it may end and be clamped on there.

As I interpret the code, the separate ground wire may daisy chain through or have taps to additional receptacles on the same branch circuit.

You may not extend the branch circuit given a ground in this fashion (or not given a ground).
 
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Old 10-18-15, 06:53 PM
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Interesting Allan, thx. From what I was reading it sounded like that was not an acceptable way to do grounding. Perhaps I read the wrong thing?
 
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Old 10-18-15, 07:34 PM
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1900's house..... so..... what is the year the house was built ?

It could almost be knob and tube. If not....maybe cloth covered.
 
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Old 10-18-15, 07:41 PM
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It's definitely cloth covered. The township information says it was built in 1900.
 
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Old 10-18-15, 07:46 PM
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Ok.... so that would be cloth covered jacket and possibly cloth covered rubber insulation on the wiring. Very brittle to work with and the insulation crumbles easily. Work carefully with it.

No ground.
 
  #13  
Old 10-18-15, 07:52 PM
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it seem to be cloth over rubber. Looked to be copper at least. It was definitely not fun stuff to work with at all since they don't leave any extra. The receptacle attached to some new wiring took me mere minutes to change. The 4 switches took me probably over an hour due to having no slack.
 
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Old 10-18-15, 07:54 PM
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It's definitely cloth covered. The township information says it was built in 1900
.

Just a guess, but I'd say the house has been rewired since it was built.
 
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Old 10-18-15, 08:03 PM
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Definitely agree that there's probably been some level of rewire. I have a mix of various vintage wire here; it's kinda like a museum, lol. Some of it is nice "new" romex. Other is icky sticky cloth stuff.

Heck for all I know there was no electrical in this home when it was first built. I'm fairly sure there wasn't a bathroom. lol. The bathroom is literally like a closet.
 
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Old 10-18-15, 08:17 PM
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Some pictures of the wires and cables would help to identify the age. Rubber insulation with cotton or linen over braid on individual conductors would tend to denote knob & tube wiring and that could be from the earliest addition of electricity to the house. Rubber insulation on copper wires has a tendency to corrode the copper so it was common to have the copper "tinned" (thin coating of tin) before the insulation was added. Plastic insulated conductors in a "cloth-covered" over braid would denote the earlier form of type NM cable, probably from the late 1940s through the 1970s.

It MAY be far easier, and definitely better, to simply pull new type NM cable to new three-prong (grounding) receptacles than to attempt to run separate equipment grounding conductors.
 
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Old 10-18-15, 08:28 PM
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Thx Furd. I think you also posted on my thread about my garage. In talking w/ the Mrs we're both thinking about the idea of running new. Most of the upstairs stuff seems to be ok, and I have af ull basement to access isn't too terrible.

There's so much janky electrical work going on in this place that to make things make more sense it would be worth doing. The bathroom, portions of the kitchen, the Mudroom and another part of the house are all on one breaker. Another portion of the kitchen is on a separate breaker, etc etc.
 
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Old 10-19-15, 07:41 AM
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I'll throw my hat into the ring with a comment that it doesn't really matter if he wiring is 80 years old or 110 years old. It's functionally obsolete and far beyond its safe, useful service life. I would look to abandon and replace the existing wiring rather than upgrade and retrofit it in place. A couple spools of Romex isn't all that expensive.
 
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Old 10-19-15, 12:33 PM
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A couple spools of Romex isn't all that expensive.
It's very easy to say... just replace it all. I just did a retrofit in plaster walls where the boxes were undersized. Buying the wire is the easy part. It's getting it to all the old boxes without opening everything up.
 
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Old 10-19-15, 01:36 PM
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Oh I get it, but as a DIY project it can be done over the course of a year. I'd rather spend my time doing the full rewire than 70% of the work fishing retrofit ground wires and gaining nothing but equipment ground. With the understanding of course that there may be a light box or switch look here and there that can't practically be replaced without wrecking the plaster work. AFCI breakers and proper grounding all around those remaining segments will go a long way to improving safety of the system.
 
  #21  
Old 10-21-15, 06:43 PM
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I looked at a 1000 ft spool of 12/2 at lowes yesterday and it was only like 200 dollars. That to me isn't too bad at all. Like stated above, it's more about replacing it all without having to tear everyhing apart (We stupidly already did some drywall on the living room. The rest of the house is panel/lathe/plaster so not as big of a deal).
 
  #22  
Old 10-21-15, 08:20 PM
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For most circuits you only need 14-2.
 
  #23  
Old 10-21-15, 08:42 PM
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that's what I was reading is that regular circuits are usually 14-2, while bathrooms and kitchens are usually 12-2 to accommodate 20amps. Would there be any harm in just using 12-2 throughout the house? I figured if 12-2 is 200 for 1000ft, 14-2 must be less
 
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Old 10-21-15, 09:36 PM
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No problem except cost and because it is larger therefore stiffer and a bit harder to work with.
 
  #25  
Old 10-22-15, 04:35 PM
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I looked at a 1000 ft spool of 12/2 at lowes yesterday and it was only like 200 dollars.
You'll quickly regret purchasing 1000 foot spools. The cost per foot is the same when purchasing 250 foot rolls and the rolls are much easier to handle and work with.
 
  #26  
Old 10-22-15, 04:46 PM
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You'll quickly regret purchasing 1000 foot spools. The cost per foot is the same when purchasing 250 foot rolls and the rolls are much easier to handle and work with.
I just price checked and it looks like about a 4 dollar difference between a full 1000ft spool and 4 250 ft spools. If tha'ts the price of convenience, I'll pay it, lol.
 
  #27  
Old 10-22-15, 05:01 PM
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I just price checked and it looks like about a 4 dollar difference between a full 1000ft spool and 4 250 ft spools. If tha'ts the price of convenience, I'll pay it, lol.
I have checked it at the store before just for kicks and the price was exactly the same. If you ask, they should make it the same considering you'll be maybe buying as many as 8 rolls.
 
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