ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat Box
Recent Posts
Lock-down Thread
by Bill Addiss - 02/27/21 01:16 PM
Northern Tool Recalls Powerhorse Generators
by Admin - 02/25/21 09:49 PM
You will never guess
by gfretwell - 02/25/21 07:48 PM
New tool
by SMOKEYBOB - 02/15/21 04:59 PM
New in the Gallery:
Facebook follies, bad wiring
FPE in Germany pt.2
Who's Online Now
1 registered members (Scott35), 21 guests, and 20 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Old work grounding stumper #192333 02/08/10 05:42 PM
Joined: Feb 2004
Posts: 115
H
Haligan Offline OP
Member
The Scene:
Old work bathroom remodel. GC has it down to the studs.
I'm keeping the existing circuit for lights and fan. 12/2 NM, no grounding
I've pulled a homerun 20a for receps.

How to ground the lights and fan?
A. There's a bare 14ga conductor that was bonding all of the old metal boxes. It is clamped with a grounding electrode to the bathroom's water pipe. This wire then continues off to other parts of the house. I could tap into this. But! Code says bonding to water pipe has to be 5' from source. This seems like a 'better than nothing' option. My least favorite so far.

B. Connect to the grounding of the new 20a circuit. This goes back to the panel and straight to the rod. Problem- I scoured the code and couldn't find an allowance for this.

C. Connect a new electrode and ground the lights and fan to the water pipe.

D. Run 12ga grounding wire all the way back to the panel. This is okay code wise, but raises some new issues.

What's best here?

2017 / 2014 NEC & Related Books and Study Guides
Re: Old work grounding stumper [Re: Haligan] #192334 02/08/10 07:52 PM
Joined: Aug 2001
Posts: 457
J
Jim M Offline
Member
Since you are down to the studs I would think that a new lighting circuit should be run.

Re: Old work grounding stumper [Re: Jim M] #192336 02/08/10 08:26 PM
Joined: Apr 2002
Posts: 7,233
HotLine1 Offline
Member
I tend to agree with Jim M.
You may want to run your list of options past the local AHJ, as he is the one to accept or reject your choice(s).



John
Re: Old work grounding stumper [Re: HotLine1] #192337 02/08/10 09:51 PM
Joined: Jul 2004
Posts: 9,569
G
gfretwell Offline
Member
Best practice would be to run a new wire. Your ideas of using the water pipe, even with another rod, won't work unless you bond back to the existing ground electrode system.
You could share the EGC of the new receptacle circuit you have run but you do have to worry about protecting the wire you run. I would ask if your AHJ is OK with just stringing a THHN over to the receptacle box

Quote
250.120(C) Equipment Grounding Conductors Smaller Than 6 AWG. Equipment grounding conductors smaller than 6 AWG shall be protected from physical damage by a raceway or cable armor except where run in hollow spaces of walls or partitions, where not subject to physical damage, or where protected from physical damage.


Greg Fretwell
Re: Old work grounding stumper [Re: gfretwell] #192338 02/08/10 10:58 PM
Joined: Jan 2004
Posts: 1,507
G
George Little Offline
Member
Guess I'm trying to figure out why anything has to be done with existing. But if you insist on doing something, item D. is the only one that meets code.


George Little
Re: Old work grounding stumper [Re: George Little] #192339 02/08/10 11:34 PM
Joined: Jul 2004
Posts: 9,569
G
gfretwell Offline
Member
I was just trying to let safety trump a technical violation (extending the EGC from an existing circuit of sufficient size). I would rather have a ground than not.


Greg Fretwell
Re: Old work grounding stumper [Re: gfretwell] #192340 02/09/10 12:38 AM
Joined: Jan 2004
Posts: 1,507
G
George Little Offline
Member
I guess I agree with you Greg and I would add, another option would be to wire the fan and lights in the bathroom on the new receptacle circuit. As long as he didn't extend to anything beyond the one bathroom, he'd have not only grounding but GFCI protection ta boot.


George Little
Re: Old work grounding stumper [Re: George Little] #192341 02/09/10 01:36 AM
Joined: Feb 2004
Posts: 115
H
Haligan Offline OP
Member
George- I'm liking 210.11(C)3. The lights and the fan sum up to less than 1amp. Plenty of leftover on the 20a dedicated.

Thanks all

Re: Old work grounding stumper [Re: George Little] #192345 02/09/10 10:29 AM
Joined: Feb 2008
Posts: 165
R
Rewire Offline
Member
Originally Posted by George Little
Guess I'm trying to figure out why anything has to be done with existing. But if you insist on doing something, item D. is the only one that meets code.
The only method that would be questionable would be B but all the others are code compliant


Featured:

2020 National Electrical Code
2020 National Electrical
Code (NEC)

* * * * * * *

2020 Master Electrician Exam Preparation Combos
2020 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
pcsailor
pcsailor
Minneapolis, MN, USA
Posts: 21
Joined: September 2019
Show All Member Profiles 
Top Posters(30 Days)
Popular Topics(Views)
275,482 Are you busy
209,385 Re: Forum
196,771 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.3