ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Recent Posts
Al Hildenbrand - Minneapolis - obituary
by Bill Addiss - 02/03/23 07:38 PM
by renosteinke - 01/27/23 09:52 PM
Does NEC 551.71 (F) apply to dwellings?
by BigB - 01/20/23 10:46 AM
Power submeter connections
by HotLine1 - 01/19/23 09:09 AM
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
1 members (Scott35), 34 guests, and 18 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Joined: Jan 2014
Posts: 7
mgawat Offline OP
New Member
220.4A and 300.3B applied to neutral bar mounted in overhead wireway.
First of, let me start by saying I am not young. I may have been lead into some possibly non complying practices over the last 50 YEARS which is WHY i ASK QUESTIONS.
The SCENARIO IS A 480/277V PANELBOARD WITH 3 2" CONDUITS EXTENDING VERTiCALLY ABOUT 40" into a A 10 X 10 X 48" WIREWAY WHICH is attached up tight to the finish ceiling. Now, in the past, we always considered that assembly as one big panelboard and once the cable conductors entered that wireway, one could pretty much do what one wants with them...i,e, install a grounding bar in the wireway to run all the branch circuit grounding conductors and so the same thing with an isolated neutral bar which saves counts on the conductor fill of the 40" 2' pipe to minimize conductor derating.

I have been doing it this way for well over 20 years until today when I was inspected by the senior state of Maine electrical Inspector. He states that 220.4A and 300.3b prohibit doing that and all the individual neutral conductors associated with each branch circuit must go all the way to the grounded terminal in the main feeder panel.

Does anyone smart out there have an opinion on this?. At one time, the State of Maine electrician's examaining board had issued an adoption stating that they would consider all electrical equipment on the same backboard as the feeder panel part of that FEEDER PANEL AND ONE COULD INSTALL THE NEUTRAL BAR WHEREVER ONE WISHED AS IT WAS NOW IN THE PANELBOARD ASSEMBLY.[

Last edited by mgawat; 07/29/19 05:09 PM.
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: May 2005
Posts: 984
Likes: 1
The Inspector is right.
Be happy that you got away with a misinterpretation for over 20 years before you got caught.

Joined: Jul 2004
Posts: 9,788
Likes: 14
I suppose 300.4(B)(4) could lead to this confusion but it does not appear that this condition applies. (2017)

(4) Column-Width Panelboard Enclosures. Where an auxiliary
gutter runs between a column-width panelboard and a pull
box, and the pull box includes neutral terminations, the
neutral conductors of circuits supplied from the panelboard
shall be permitted to originate in the pull box.

Greg Fretwell
Joined: Apr 2002
Posts: 7,333
Likes: 7
The column width panels that I have seen over the years (few & far between) have had a neutral bar in the pull box section that was supplied with the panelboard as a complete unit. ie: 'Factory supplied' with documentation regarding the size of the neutral conductor stated.

As I said, few and far inbetween.

Joined: Jan 2014
Posts: 7
mgawat Offline OP
New Member
the adoption of 220.4 (b) IN THE 2011 nec CODE pretty much says I can't sdo that any longer but I still don't understand the concern especially with non-metallic conduits running between the panelboard and the metallic wireway 40" away.

Joined: Jan 2018
Posts: 31
A bit confused. The last time there was an Article 220.4 in the NEC was in the 2002 edition. In 2005 NEC articles in 220 were renumbered and 220.4 became 220.18. In any case, the old 220.4 and present 220.18 address maximum loads.

Link Copied to Clipboard

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
Bakersfield, CA (Originally Orange Co.)
Posts: 1,438
Joined: February 2004
Top Posters(30 Days)
triple 3
Popular Topics(Views)
303,267 Are you busy
232,240 Re: Forum
216,990 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.5