ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
Increasing demand factors in residential
by gfretwell - 03/28/24 12:43 AM
Portable generator question
by Steve Miller - 03/19/24 08:50 PM
Do we need grounding?
by NORCAL - 03/19/24 05:11 PM
240V only in a home and NEC?
by dsk - 03/19/24 06:33 AM
Cordless Tools: The Obvious Question
by renosteinke - 03/14/24 08:05 PM
New in the Gallery:
This is a new one
This is a new one
by timmp, September 24
Few pics I found
Few pics I found
by timmp, August 15
Who's Online Now
1 members (Scott35), 266 guests, and 14 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 2 1 2
Joined: Mar 2003
Posts: 849
Y
Member
600 volt three conductor (310.20??), or 4160 three conductor(310.73??) either with messager.
Yoopersup

Stay up to Code with the Latest NEC:


>> 2023 NEC & Related Reference & Exam Prep
2023 NEC & Related Reference & Study Guides

Pass Your Exam the FIRST TIME with the Latest NEC & Exam Prep

>> 2020 NEC & Related Reference & Study Guides
 

Joined: Jul 2004
Posts: 9,923
Likes: 32
G
Member
If the 3 conductors are in a metal jacket I don't think any "free air" table applies (one opinion).


Greg Fretwell
Joined: Jan 2005
Posts: 5,445
Likes: 2
Cat Servant
Member
IMO: Not only do you use the 'standard' table (310.16), but you might even have to derate for heat (in the sun), as you wpould were they over a rooftop.

I believe the 2008 also would require this MC to be in a waterproof jacket as well.

Joined: Mar 2003
Posts: 849
Y
Member
310.73 MV : In Isolated CONDUIT in air. So that one I;m pretty sure of.
310.18 LV : Not sure of?

Joined: Nov 2007
Posts: 764
K
Member
For the 600V, I think you may need to use Table B.310.3 in Annex B, since it specifically mentions type MC cable in free air.
For over 2000V though, with three conductors, I believe you could use table 310.71, since IMO, the MC jacket is not actually a conduit or raceway as defined in Art.100.

Joined: Nov 2007
Posts: 764
K
Member
I probably should have said you may want to use Table B.310.3 in Annex B.

Joined: Jul 2007
Posts: 1,335
S
Member
Just carious, why are you stringing MC on a messager? Or am just interpting something wrong here?


"Live Awesome!" - Kevin Carosa
Joined: Mar 2003
Posts: 849
Y
Member
MC cable on Industrial sites is quite often put on poles to remote pumping stations ect. Both 600v & i;ve even see 15kv in MC on poles.
Yoopersup

Joined: Jul 2004
Posts: 9,923
Likes: 32
G
Member
I have never seen it before either, which tends to explain my silly answer above, sorry for the confusion. wink


Greg Fretwell
Joined: Mar 2003
Posts: 849
Y
Member
mc cable 330.10 (B)4.

Installed outside of buildings or structures or as aerial cable.
type mc cable installed outside of buildings or structures or as aerial cable shall comply with 225.10,396.10,& 396.12.

Page 1 of 2 1 2

Link Copied to Clipboard
Powered by UBB.threads™ PHP Forum Software 7.7.5