The Electrical Contractor Network

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

Books, Tools and Test Equipment for Electrical and Construction Trades

Register Now!

Register Now!

We want your input!

Featured Items:

Switch Bit - Interchangeable Flex Bit System
>> Switch Bit -
Interchangeable Flex Bit System

>> 2014 NEC and Related

Recent Posts
A question for RODALCO
by electure
Today at 06:28 AM
Motor start, motor run capacitors
by Tesla
03/30/15 03:24 PM
Service disconnect
by Mitch65
03/30/15 12:35 PM
"Forbidden" Fittings?
by gfretwell
03/30/15 09:26 AM
Look at What an Ex-Tenant Left Behind
by HotLine1
03/29/15 03:35 PM
New in the Gallery:
What's behind the door???
Shout Box

Top Posters (30 Days)
Tesla 24
HotLine1 23
gfretwell 22
sparkyinak 13
renosteinke 13
Who's Online
0 registered (), 110 Guests and 4 Spiders online.
Key: Admin, Global Mod, Mod
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
2014 / 2011 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: 2561
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: 3324
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: 577
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



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