ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
Potseal 11
Recent Posts
Dimmable LED 2x4 lay in fixtures
by Potseal. 04/23/17 07:18 PM
Old decora style outlets
by Lostazhell. 04/22/17 07:59 PM
Permit Snafus...AHJs and Contractors Jump in
by gfretwell. 04/22/17 01:11 PM
How do you find a good employee?
by HotLine1. 04/22/17 10:44 AM
Electrode boilers question
by SteveFehr. 04/21/17 08:32 AM
New in the Gallery:
SE cable question
Popular Topics(Views)
234,650 Are you busy
169,334 Re: Forum
162,672 Need opinion
Who's Online Now
0 registered members (), 86 guests, and 10 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
Page 1 of 2 1 2
#86679 - 11/19/03 09:25 PM Grounding method question  
Jim M  Offline
Member
Joined: Aug 2001
Posts: 457
Chestertown, MD, USA
I was just in a older (about 30-40 years) house that I think has metal framing. It appears that the wiring was 2 conductor NM. A ground wire has been run between the box and the device. It seems like they were using the framing to achieve the ground connection. A plug-in checker shows the devices are wired properly. I don't think that this is the way it should be, but don't have enough info to make an informed decision. What options should I tell the owner are available?

Thanks,
Jim


2017 / 2014 NEC & Related Books and Study Guides

#86680 - 11/20/03 06:25 AM Re: Grounding method question  
sparky  Offline
Member
Joined: Oct 2000
Posts: 5,306
first off~ this may have been compliant to the '63 nec....

secondly, there are newly marketed goodies to enhance the safety of older wiring, such as AFCI's

btw~ i would be very careful to offer anything more than 'enhancement' with these...


#86681 - 11/20/03 08:01 AM Re: Grounding method question  
Redsy  Offline
Member
Joined: Mar 2001
Posts: 2,056
Bucks County PA
I'm not a construction expert, but metal framing on a 30-40 year old house seems unusual.
Maybe the boxes are grounded but you can't see it. From behind?


#86682 - 11/20/03 10:35 AM Re: Grounding method question  
Ryan_J  Offline
Moderator
Joined: Aug 2003
Posts: 1,374
West Jordan, Utah, USA
I would be very concerned if the framing of the house is used as an equipment grounding conductor...


Ryan Jackson,
Salt Lake City

#86683 - 11/20/03 10:20 PM Re: Grounding method question  
stamcon  Offline
Member
Joined: Mar 2001
Posts: 329
So San Francisco CA
Jim, some of the old houses I deal with, use a small(16 gauge?) bare copper wire that runs throughout the house, "connected" to the boxes by wrapping several turns around a nail that attaches the box to the stud. The wire would terminate at a water pipe with a strap. The wire is tee tapped, by wrapping the tap around the main wire and soldering, just like knob and tube wiring. Sometimes it's just the kitchen and bath that have the wire.


#86684 - 11/22/03 02:20 AM Re: Grounding method question  
PCBelarge  Offline
Member
Joined: Jun 2003
Posts: 681
Dobbs Ferry, NY, USA
Using the structural steel, or a grounding conductor that is not run with the phase conductors may not ensure that the ground fault current path is effective.

250.4(A)(5) Effective Ground-Fault Current Path. requires this path to be effective, therefore that would not be a proper method.

I know that the code permits a grounding conductor to be run to the nearest equipment grounding conductor, 250.130(C), but I say this is asking for trouble.

Pierre


Pierre Belarge

#86685 - 11/22/03 12:08 PM Re: Grounding method question  
Bill Addiss  Offline
Member
Joined: Oct 2000
Posts: 3,878
NY, USA
Quote
some of the old houses I deal with, use a small(16 gauge?) bare copper wire that runs throughout the house, "connected" to the boxes by wrapping several turns around a nail that attaches the box to the stud
Stamcon,

I've seen that too, usually for Kitchens. Never seen Copper though, the ones I've seen seem to be Aluminum. They sometimes go from each device box up to the attic and are twisted together, or joined by some other questionable means. Many times these wires are cut or broken and not repaired simply because no one knows what they are.

I had some pictures around, but can't seem to locate them right now.

Bill


#86686 - 11/23/03 02:56 PM Re: Grounding method question  
electure  Offline


Member
Joined: Dec 2000
Posts: 4,259
Fullerton, CA USA
Is there no ground wire at all?
All the metal boxes in my house were grounded with a bare #12 that was daisy chained from the back of one box to the back of another, then to ground in the service.
It wasn't run with anything else,just by itself. It apparently was Code compliant at the time ('58). I've seen lots done this way.


#86687 - 11/26/03 02:14 AM Re: Grounding method question  
Bill Addiss  Offline
Member
Joined: Oct 2000
Posts: 3,878
NY, USA
Here's a Photo sent to me by Joe Tedesco showing a Ground wrapped around a nail:

[Linked Image]


#86688 - 11/27/03 12:15 AM Re: Grounding method question  
PCBelarge  Offline
Member
Joined: Jun 2003
Posts: 681
Dobbs Ferry, NY, USA
Look at the nail going through the lower portion of the gem box.

Pierre


Pierre Belarge

Page 1 of 2 1 2

Member Spotlight
watersparkfalls
watersparkfalls
Washington...Not DC
Posts: 216
Joined: March 2005
Show All Member Profiles 
Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.017s Queries: 15 (0.003s) Memory: 0.8163 MB (Peak: 0.9951 MB) Zlib enabled. Server Time: 2017-04-24 15:20:29 UTC