ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
Does NEC 551.71 (F) apply to dwellings?
by BigB - 01/20/23 10:46 AM
Violation?
by HotLine1 - 01/19/23 09:10 AM
Power submeter connections
by HotLine1 - 01/19/23 09:09 AM
AFDD's coming to the UK
by Texas_Ranger - 01/17/23 07:22 PM
Circuit Breaker Lube
by renosteinke - 01/14/23 06:40 PM
New in the Gallery:
Burger King crown sillyness
Burger King crown sillyness
by wa2ise, December 11
240/208 to a house
240/208 to a house
by wa2ise, October 9
Who's Online Now
0 members (), 12 guests, and 15 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Joined: Feb 2004
Posts: 494
M
Member
If a circuit supplies a fluorescent, mercury or metal halide do the neutrals still have to be counted as current carrying? This neutral will carry a third harmonic.

Thanks for any replies

Greg

Stay up to Code with the Latest NEC:


2020 NEC & Related Reference & Study Guides
2020 NEC & Related Reference & Study Guides
Pass Your Exam the FIRST TIME with these Exam Prep Combos:
 

>> Master Electrician Exam Prep     >> JourneyMan Electrician Exam Prep
 

Joined: Aug 2003
Posts: 1,374
R
Moderator
Yes, any non-linear(harmonic) load creates a current carrying nuetral.


Ryan Jackson,
Salt Lake City
Joined: Nov 2000
Posts: 2,148
R
Member
Only on 3 phase systems.
Don


Don(resqcapt19)
Joined: Oct 2000
Posts: 2,749
Member
... and only when that nonlinear load is the major portion (over 50%) ....

See the 2005 NEC .....

Nonlinear Load. A load where the wave shape of the steady-state current does not follow the wave shape of the applied voltage.

Article 310

(c) On a 4-wire, 3-phase wye circuit where the major portion of the load consists of nonlinear loads, harmonic currents are present in the neutral conductor; the neutral shall therefore be considered a current-carrying conductor.
FPN: Electronic equipment, electronic/electric-discharge lighting, adjustable-speed drive systems, and similar equipment may be nonlinear loads.


Joe Tedesco, NEC Consultant
Joined: Jul 2004
Posts: 9,788
Likes: 14
G
Member
You can still induce out of phase currents in a single phase neutral (multiwire circuit) but you won't get the overload effect you get in 3 phase. It can still make measurememnts not balance if your meter isn't true RMS.


Greg Fretwell

Link Copied to Clipboard
Featured:

Tools for Electricians
Tools for Electricians
 

* * * * * * *
2023 National Electrical Code (NEC)
2023 NEC Now Available!
 
* * * * * * *

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

 

Member Spotlight
Grover
Grover
Sebago, ME, USA
Posts: 109
Joined: January 2005
Top Posters(30 Days)
BigB 9
Popular Topics(Views)
302,347 Are you busy
231,744 Re: Forum
216,374 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.5