ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
AreMetal Ladders Ever OK For Electrical Work?
by gfretwell. 01/22/18 01:15 AM
VDE 0100 to introduce AFCIs
by sparky. 01/20/18 05:09 PM
MRI LED lights dimmer control replacement - wow!
by Potseal. 01/19/18 08:52 PM
Video: Inventor of the GFCI self-testing shocks
by Bill Addiss. 01/17/18 11:11 PM
New in the Gallery:
Housebilding DIY wiring
SE cable question
Who's Online Now
0 registered members (), 12 guests, and 9 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 2 1 2
Grounding method question #86679
11/19/03 08:25 PM
11/19/03 08:25 PM
J
Jim M  Offline OP
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
Re: Grounding method question #86680
11/20/03 05:25 AM
11/20/03 05:25 AM
S
sparky  Offline
Member
Joined: Oct 2000
Posts: 5,344
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...

Re: Grounding method question #86681
11/20/03 07:01 AM
11/20/03 07:01 AM
R
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?

Re: Grounding method question #86682
11/20/03 09:35 AM
11/20/03 09:35 AM
R
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
Re: Grounding method question #86683
11/20/03 09:20 PM
11/20/03 09:20 PM
S
stamcon  Offline
Member
Joined: Mar 2001
Posts: 330
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.


Steve
Re: Grounding method question #86684
11/22/03 01:20 AM
11/22/03 01:20 AM
P
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
Re: Grounding method question #86685
11/22/03 11:08 AM
11/22/03 11:08 AM
Bill Addiss  Offline
Member
Joined: Oct 2000
Posts: 3,890
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

Re: Grounding method question #86686
11/23/03 01:56 PM
11/23/03 01:56 PM
electure  Offline

Member
Joined: Dec 2000
Posts: 4,264
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.

Re: Grounding method question #86687
11/26/03 01:14 AM
11/26/03 01:14 AM
Bill Addiss  Offline
Member
Joined: Oct 2000
Posts: 3,890
NY, USA
Here's a Photo sent to me by Joe Tedesco showing a Ground wrapped around a nail:

[Linked Image]

Re: Grounding method question #86688
11/26/03 11:15 PM
11/26/03 11:15 PM
P
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

Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
dougwells
dougwells
kamloops BC Canada
Posts: 1,142
Joined: May 2003
Show All Member Profiles 
Top Posters(30 Days)
Admin 21
sparky 16
Potseal 15
Popular Topics(Views)
243,592 Are you busy
180,388 Re: Forum
170,861 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.020s Queries: 15 (0.004s) Memory: 1.0234 MB (Peak: 1.2011 MB) Zlib enabled. Server Time: 2018-01-22 14:10:30 UTC