ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
12 Lead Motor Connection Weird
by emolatur - 01/19/22 02:40 PM
Any women electricians here?
by gfretwell - 01/17/22 01:44 PM
Well There's your problem.
by gfretwell - 01/08/22 12:17 AM
Happy New Year!!
by HotLine1 - 01/04/22 09:50 AM
Sangamo s309.2
by Robski - 12/31/21 04:54 PM
New in the Gallery:
240/208 to a house
240/208 to a house
by wa2ise, October 9
Now you know.
Now you know.
by Tom_Horne, September 7
Who's Online Now
0 members (), 40 guests, and 10 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
#215727 07/07/15 07:50 PM
Joined: Apr 2002
Posts: 189
T
triple Offline OP
Member
Does 110.26(A) apply to variable frequency drives controlling hvac related pumps? The wording of the article (and the commentary in the NEC Handbook) definitely seems to suggest that vfd's require working space. However, the electrical inspector is allowing them to be buried behind the motors and pumps. "Examining, adjusting, serving, and maintaining" these "controls" for "heating and air-conditioning equipment" now requires standing over/on or straddling the motor/pump unit.

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: Apr 2002
Posts: 7,288
Likes: 4
Member
triple:
Based on what you say, IMHO I would say 'red tag'.



John
Joined: May 2005
Posts: 984
Likes: 1
G
Member
I agree...red tag.


Ghost307
Joined: Sep 2002
Posts: 131
T
Member
I looked through 430 to see if there were any exceptions for Adjustable Speed Drives. I could not find any. So, IMO 110.26 applies.

"430.120 General. The installation provisions of Part I
through Part IX are applicable unless modified or supplemented
by Part X."


I could not find anything in Part 1 through 10 to suggest anything with regards to working space. I would have hoped that it pointed you to 110.26 at some point but it does not.

Some people consider a VFD a motor control center and if you look at it that way you would need to comply with 110.26F. I don't believe that it is a MCC since there is a clear section in 430.120 specifically providing rules for Adjustable Speed Drives (VFD's)...

IMO 110.26 A as you suggest is the winner.

Last edited by tsolanto; 07/25/15 08:52 AM.
Joined: Sep 2002
Posts: 131
T
Member
All that being said, here in NYC believe it or not we are still on the 2008 NEC so my commentary is based on that. I don't know which edition you are working with, not sure if it would matter in this case either.

Joined: Apr 2002
Posts: 7,288
Likes: 4
Member
IMHO, there are no differences within '11 or '14 regarding this.

NJ is still on'11, and I don't recall anything from '14 from "the changes" although I still admit to have a lot of reading....



John

Link Copied to Clipboard
Featured:

Tools for Electricians
Tools for Electricians
 

* * * * * * *

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

 

Member Spotlight
Posts: 362
Joined: April 2003
Top Posters(30 Days)
grich 1
Popular Topics(Views)
288,107 Are you busy
220,210 Re: Forum
206,191 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.5