ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals

Topic Options
Rate This Topic
#85635 - 07/25/03 11:00 AM Working space around transformers
steve66 Offline
Member
Registered: 03/13/03
Posts: 25
Does the working space in Article 110.26 apply to transformers? Would a 480V panelboard across the isle from a 480 to 208 transformer require 4' between them? Also, do the working space requirements apply to the sides of the transformer? If not, how much space would required on the sides to run conduit in and pull wire (aren't transformers usually fed with a LB into to side?) I am laying out an electrical room, but I'm not an electrician, and I'm not sure how the connections to transformers are usually made.

Finally, can the transformer be backed right up aginst a wall, or does it need breathing room behind it?
Top
2017 / 2014 NEC & Related Books and Study Guides
#85636 - 07/25/03 12:13 PM Re: Working space around transformers
Bjarney Offline
Moderator
Registered: 04/10/02
Posts: 2527
Loc: West-Southern Inner-Northeast ...
99NEC 450-9. Transformers with ventilating openings shall be installed so that the ventilating openings are not blocked by walls or other obstructions. The required clearances shall be clearly marked on the transformer.

110-16 working clearances would not be modified by ventilation clearances.
Top
#85637 - 07/25/03 08:17 PM Re: Working space around transformers
Joe Tedesco Offline
Member
Registered: 10/07/00
Posts: 2749
Loc: Boston, Massachusetts USA
Quote:
450.13 Accessibility.

All transformers and transformer vaults shall be readily accessible to qualified personnel for inspection and maintenance ...
_________________________
Joe Tedesco, NEC Consultant
Top
#85638 - 07/26/03 04:33 AM Re: Working space around transformers
Ron Offline
Member
Registered: 03/13/02
Posts: 582
Loc: White Plains, NY
Working clearances are required to perform preventative maintenance on the xfmr. Granted that most PM can be done with the xfmr not energized, but some will be done live (such as infrared measurements). You will need at least condition 2, possibly condition 3 depending on the interpretation of the AHJ.

[This message has been edited by Ron (edited 07-26-2003).]
_________________________
Ron
Top

Member Spotlight
Member Since: 01/22/05
Posts: 5316
New in the Gallery:
SE cable question
Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box


Who's Online
0 registered (), 54 Guests and 8 Spiders online.
Key: Admin, Global Mod, Mod
 
New in the Gallery:
SE cable question
 
Top Posters (30 Days)
Admin 51
HotLine1 43
gfretwell 17
Trumpy 16
Ruben Rocha 13
 
Newest Members
clee512, Jdscott2005, FAIZAN, Regitest2, sureshazhagai

ECN Electrical Forums - sponsored by Electrical Contractor Network - Electrical and Code Related Discussion for Electrical Contractors, Electricians, Inspectors, Instructors, Engineers and other related Professionals