ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
Video: Inventor of the GFCI self-testing shocks
by Bill Addiss. 01/17/18 11:11 PM
FPE in Germany
by HotLine1. 01/17/18 07:07 PM
VDE 0100 to introduce AFCIs
by LongRunner. 01/17/18 10:32 AM
Fujifilm Recalls Power Adapter Wall Plugs
by Admin. 01/16/18 07:04 PM
Air Compressor feeder conductor sizing
by Potseal. 01/15/18 09:08 PM
New in the Gallery:
Housebilding DIY wiring
SE cable question
Who's Online Now
0 registered members (), 14 guests, and 10 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Gray as hot conductor? #82697
12/08/02 10:27 AM
12/08/02 10:27 AM
P
pauluk  Offline OP
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
I'm looking at 200.7 of the '02 code, relating to the identification of grounded counductors.

There's an FPN at the end of this section:

Quote
FPN: The color gray may have been used in the past as an ungrounded conductor. Care should be taken when working on existing systems.


So when did the NEC first specify that gray be reserved for neutral along with white?

I believe you've all said that the BOY system (with gray for neutral) has been in common use for 277/480 for at least 30 years, so I assume that we're going back a fair way.




[This message has been edited by pauluk (edited 12-08-2002).]

2017 / 2014 NEC & Related Books and Study Guides
Re: Gray as hot conductor? #82698
12/08/02 11:47 AM
12/08/02 11:47 AM
R
resqcapt19  Offline
Member
Joined: Nov 2000
Posts: 2,148
IL
Paul,
Actually this change was made in the 2002 code. Prior to that the code used the words "natural gray". This is an old term from the early years of thermoplastic insulations and was a "natural" color, that is colorants were not added when the insulating material was made. "Natural gray" has not been available for 30 to 40 years. The use of wire with a gray insulation as a grounded conductor prior to the '02 code was actually a code violation, even though it was also a very common practice. There have been atempts to make this code change in 3 or 4 code cycles prior to the '02 but they were not accepted. All of these proposals cited the common practice of using the manufactured color gray in place of the required "natural gray", but it wasn't until the '02 that a proposal was accepted. The fine print note was added because, even though it was common practice to use the manufactured color gray for the grounded conductor, this color was permitted to be used as a hot conductor. Just another reason why we should never rely on wire colors to determine the voltage and function of a conductor.
Don


Don(resqcapt19)
Re: Gray as hot conductor? #82699
12/08/02 12:51 PM
12/08/02 12:51 PM
C
CTwireman  Offline
Member
Joined: Feb 2002
Posts: 840
Connecticut, USA
Quote
Just another reason why we should never rely on wire colors to determine the voltage and function of a conductor.


That bears repeating. Everyone has a horror story relating to mis-use of colors!


Peter
Re: Gray as hot conductor? #82700
12/08/02 05:57 PM
12/08/02 05:57 PM
S
sparky806  Offline
Member
Joined: Dec 2002
Posts: 59
Shawnee, KS, USA
Here in my area, Kansas City, grey is commonly used as the "B" phase on a 240 volt grounded B system. Although this is a 3 phase system, it is normally installed with single phase equipment. It can really confuse the newer guys when they see 240 volts from hot to "nuetral".

Re: Gray as hot conductor? #82701
12/08/02 08:41 PM
12/08/02 08:41 PM
G
Gwz  Offline
Member
Joined: Apr 2002
Posts: 197
The single phase equipment used on the grounded 240V 3Ø 3W system should be indentified by the equipment manufacturer as be 'suitable for use' on a Grounded 3Ø 3W system.

Re: Gray as hot conductor? #82702
12/09/02 07:03 PM
12/09/02 07:03 PM
P
pauluk  Offline OP
Member
Joined: Aug 2001
Posts: 7,520
Norfolk, England
Ah, natural gray.... I recall some discussions about this change of terminology from some months ago now.

I've since noticed a similar FPN on some other NEC articles, all with the bar at the side to indicate new or altered entries.


Featured:

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

 

Member Spotlight
HotLine1
HotLine1
Brick, NJ USA
Posts: 6,917
Joined: April 2002
Show All Member Profiles 
Top Posters(30 Days)
sparky 20
Admin 20
Potseal 13
Popular Topics(Views)
243,537 Are you busy
180,340 Re: Forum
170,829 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.019s Queries: 14 (0.003s) Memory: 0.9754 MB (Peak: 1.1199 MB) Zlib enabled. Server Time: 2018-01-18 15:54:28 UTC