ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat Box
Recent Posts
120/208 gives 240? please clarify
by gfretwell - 07/15/20 06:07 PM
Code Violation or just not good Practice?
by gfretwell - 07/15/20 06:01 PM
NESC question
by gfretwell - 07/15/20 03:40 PM
Questioning the electrical norms
by HotLine1 - 07/13/20 12:40 PM
You will never guess
by BigB - 07/13/20 09:45 AM
New in the Gallery:
Facebook follies, bad wiring
FPE in Germany pt.2
Who's Online Now
0 registered members (), 16 guests, and 12 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 2 1 2
Reduced grounding wire in NMC #220515 03/07/20 02:35 PM
Joined: Jan 2004
Posts: 1,507
G
George Little Offline OP
Member
I've been asked to get an opinion on what to do with the reduced size bare wire in NMC where in older houses we find it terminated by wrapping it around the cable clamp. Can we use that wire to connect it to the green screw on a replacement receptacle? The original receptacle was an ungrounded two wire receptacle. My opinion is that you can not use this a an equipment grounding conductor based on what it says at NEC Article 250.122(A). What say you guys?


George Little
2017 / 2014 NEC & Related Books and Study Guides
Re: Reduced grounding wire in NMC [Re: George Little] #220516 03/09/20 10:17 AM
Joined: Jul 2004
Posts: 9,509
G
gfretwell Online Content
Member
I personally think a 16ga wire will operate a 15a O/C device if it was made up properly and even though it doesn't meet current code I would certainly use it but I agree it doesn't meet the current code for an EGC. The legal fix is going to be a GFCI. Perhaps these days a GFCI/AFCI device is the way to go if you can find one to fit the existing panel. Since that RX screams "Happy days" (1950-65) I doubt the panel will take any new style breakers at all unless it was replaced along the way. You may be tracking down the first receptacle on the circuit and using a device type GFCI.
My house has the 16ga EGC in the original wiring but I figured out the boxes are made up almost like you would see today with the grounds twisted up tight, connected by a screw to the box and a pigtail to the receptacle so I have been treating them normally. The kitchen and both bathrooms were renovated and the wiring upgraded. There are really not that many 3 prong plugs used in the rest of the house anyway when you think about it. The garage was built in 1970 with full size ground cable.


Greg Fretwell
Re: Reduced grounding wire in NMC [Re: gfretwell] #220517 03/09/20 10:34 AM
Joined: Jan 2004
Posts: 1,507
G
George Little Offline OP
Member
Mr. Fretwell, I know what you are saying and sympathize with ya. Here's what I also wonder. Why did they start running that 18 gage wire in the first place? Also, in this day and age if you are brought before 12 honest men, all they know is that the code says a #14 gage wire is required for use on a 15 ampere branch circuit. That's the world we live in. The law is the law. 🙂


George Little
Re: Reduced grounding wire in NMC [Re: George Little] #220518 03/09/20 01:39 PM
Joined: Apr 2002
Posts: 7,186
HotLine1 Offline
Member
George:

Here in NJ, under the UCC and presently the 2017 NEC for new work.

The replacement of devices terminated on the EXISTING wiring does NOT require a permit. Therefore, this is a moot issue for NJ.

Now, take that EXISTING branch circuit with "old" NM and try to extend it, and then it becomes an issue, as a permit, and compliance with the NEC is required.

Yes, you are 100% correct regarding the undersized EGC based on the 'current' NEC, but I have to follow the above statement.

Stay safe & healthy.


John
Re: Reduced grounding wire in NMC [Re: George Little] #220520 03/09/20 08:22 PM
Joined: Jul 2004
Posts: 9,509
G
gfretwell Online Content
Member
I think the down size neutral started when there was no neutral at all required. They based it on the same thinking that an 18ga wire was OK in a fixture or line cord that could be on a 20a circuit. It will not handle that current in an overload situation but it will operate the OC device with a bolted fault.
We do use down sized neutrals in cables larger than #10 in compliance with 250.122.


Greg Fretwell
Re: Reduced grounding wire in NMC [Re: gfretwell] #220522 03/09/20 08:39 PM
Joined: Jan 2004
Posts: 1,507
G
George Little Offline OP
Member
Greg, I think you are talking about a "downsized neutral" which I've never heard of, the subject is the downsized bare wire in the old romex cable. The bare conductor in the old romex was used in the cable and usually wrapped around the screw used for the cable clamp. There was no tapped hole for installing a screw for the "ground/bonding" conductor. Please explain. 😉


George Little
Re: Reduced grounding wire in NMC [Re: George Little] #220523 03/09/20 10:01 PM
Joined: Jul 2004
Posts: 9,509
G
gfretwell Online Content
Member
Sorry, I mis spoke, down sized EGC.
Typically I saw boxes fed from the top and the bottom unused clamp was removed they wrapped the bare wire around the screw and reinstalled the clamp. That was twisted tight to the outgoing RX ground (usually 2" or twist or more) and they left a stinger for the receptacle.
The argument was the fillister head screw on the clamp was not suitable for a binding screw but using the clamp as a washer was OK.


Greg Fretwell
Re: Reduced grounding wire in NMC [Re: gfretwell] #220524 03/10/20 12:34 PM
Joined: Jan 2004
Posts: 1,507
G
George Little Offline OP
Member
No one has answered my question yet. Why was the manufacturer installing a reduced size wire in the NM cable anyway? It wasn't doing anything.


George Little
Re: Reduced grounding wire in NMC [Re: George Little] #220526 03/10/20 08:03 PM
Joined: Jan 2018
Posts: 13
L
libellis Offline
Member
Once upon a time there was no requirement for residential NM to have an EGC. Eventually, there was an NEC requirement (early 1960's) for branch circuits to have an EGC, but not until a few years later did the NEC tighten the requirement by specifying a minimum gauge for it. Before that manufacturers could and did make NM with a reduced gauge EGC. The most likely reason why is probably the most obvious - cost.

Re: Reduced grounding wire in NMC [Re: libellis] #220527 03/10/20 09:13 PM
Joined: Jan 2004
Posts: 1,507
G
George Little Offline OP
Member
Good answer Libellis, I agree with your logical chain of events. I would only add one thing- They increased the size of the conductor when 250.122 came in the code. Thanks for your input.


George Little
Page 1 of 2 1 2

Featured:

2020 National Electrical Code
2020 National Electrical
Code (NEC)

* * * * * * *

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

 

Member Spotlight
Posts: 362
Joined: April 2003
Show All Member Profiles 
Top Posters(30 Days)
Admin 8
Popular Topics(Views)
267,461 Are you busy
202,088 Re: Forum
190,650 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.3