ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat Box
Recent Posts
Split Bus Breaker Panel
by gfretwell - 01/25/21 12:35 AM
Ground fault remover :-)
by dsk - 01/24/21 04:35 AM
Questioning the electrical norms
by Trumpy - 01/24/21 03:16 AM
From an outsider- How does tipping work?
by gfretwell - 01/23/21 06:13 PM
Photo Editing Software?
by JoeTestingEngr - 01/23/21 12:47 PM
New in the Gallery:
Facebook follies, bad wiring
FPE in Germany pt.2
Who's Online Now
0 registered members (), 19 guests, and 14 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Free Air #84860 05/13/03 02:22 PM
Joined: Mar 2003
Posts: 15
B
boxford Offline OP
Member
Referencing Table 310.19 it states the following:

Table 310.19 Allowable Ampacities of Single-Insulated Conductors, Rated 0 Through 2000 Volts, 150 degrees Through 250 degrees (302 degrees F Through 482 degrees F), in Free Air, Based on Ambient Air Temperature of 40 degrees C (140 degrees F)

Does anyone know of a reference that specifically states the definition of "Free Air"?

I appreciate anyones help.
Brian

2017 / 2014 NEC & Related Books and Study Guides
Re: Free Air #84861 05/13/03 05:26 PM
Joined: Apr 2002
Posts: 7,227
HotLine1 Offline
Member
Boxford:
I'll take a stab at "free air"...
The best street definition I can come up with is an installation as the utility companies use. Single conductors mounted on cross arms or similar approved methods on poles. I could take it a step further and mention the "older" rack service drops at some commercial buildings; a "rack" is mounted to the exterior wall, on which insulators are mounted, and individual conductors are mounted to the insulators. This is not a commonly used installation now.
Hope this helps
John


John
Re: Free Air #84862 05/13/03 06:05 PM
Joined: Jul 2002
Posts: 175
E
electric-ed Offline
Member
Single conductors, spaced more than one diameter apart in a ventilated (ladder type) cable tray, are usually considered to be "free air".

Ed

Re: Free Air #84863 05/13/03 07:06 PM
Joined: Oct 2000
Posts: 5,389
S
sparky Offline
Member
and i thought i could fill my tires for free here, so much for livin' in the past eh? [Linked Image]

Re: Free Air #84864 05/14/03 07:52 AM
Joined: Mar 2003
Posts: 15
B
boxford Offline OP
Member
I really appreciate everyones help.

Brian


Featured:

2020 National Electrical Code
2020 National Electrical
Code (NEC)

* * * * * * *

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

 

Member Spotlight
Vlado
Vlado
Croatia
Posts: 28
Joined: February 2011
Show All Member Profiles 
Top Posters(30 Days)
Trumpy 18
NORCAL 12
Popular Topics(Views)
274,162 Are you busy
207,976 Re: Forum
195,725 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.3