ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
twh 3
Recent Posts
Nec circuit protection
by Yoopersup. 11/22/17 03:22 PM
FPE in Germany
by Texas_Ranger. 11/19/17 07:30 AM
Ceiling fan distance from outdoor hot tub
by gfretwell. 11/16/17 02:18 AM
diazed fuses
by Texas_Ranger. 11/13/17 03:02 PM
Theft deterrent alarm
by gfretwell. 11/12/17 01:39 PM
New in the Gallery:
Gallery Test
Popular Topics(Views)
242,655 Are you busy
178,867 Re: Forum
170,083 Need opinion
Who's Online Now
1 registered members (gfretwell), 19 guests, and 6 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
Page 1 of 2 1 2
#213321 - 04/10/14 01:29 PM 13.8 volts in conduit  
Yoopersup  Offline
Member
Joined: Mar 2003
Posts: 835
Michigan
Question
13800 volt cables in conduit,
Two cables (Feeder in Feeder out).
Can they be run in same conduit if correct
sq inch of fill??
Conduit RSC but could be any type raceway.
Yoopersup


2017 / 2014 NEC & Related Books and Study Guides

#213322 - 04/10/14 02:19 PM Re: 13.8 volts in conduit [Re: Yoopersup]  
HotLine1  Offline


Member
Joined: Apr 2002
Posts: 6,874
Brick, NJ USA
Art 215 seems not to address this in the over 600v sections.

Sounds like a design issue with the info you provided. OCP, conductor sizes, what the 'in' & 'out' are, etc., and time to research may all be needed. Derating may be required.

Scott35 what say you??


John

#213323 - 04/10/14 05:07 PM Re: 13.8 volts in conduit [Re: Yoopersup]  
gfretwell  Online Content


Member
Joined: Jul 2004
Posts: 9,136
Estero,Fl,usa
I am sure you are be derating this to 80% (4-6 conductors) but I can't think of a code reason why it would be prohibited.
If one set was service conductors it is a problem.


Greg Fretwell

#213324 - 04/10/14 05:11 PM Re: 13.8 volts in conduit [Re: Yoopersup]  
Yoopersup  Offline
Member
Joined: Mar 2003
Posts: 835
Michigan
310.60 Conductors Rated 2001 to 35,000 Volts.
Derateing HV conductors.
I don't think their done the same as under 600 volts.


#213325 - 04/10/14 06:38 PM Re: 13.8 volts in conduit [Re: Yoopersup]  
gfretwell  Online Content


Member
Joined: Jul 2004
Posts: 9,136
Estero,Fl,usa
Watts is watts and that means heat. I bet if you run that formula you will end up being in the same place.

I suppose you should just demand the calculation because there is not a table for 4-6 conductors.
I am just a "pump and pulley" guy and that sort of math makes my head hurt. wink


Greg Fretwell

#213326 - 04/10/14 06:55 PM Re: 13.8 volts in conduit [Re: Yoopersup]  
Yoopersup  Offline
Member
Joined: Mar 2003
Posts: 835
Michigan
Can you even put more then 3 Phase conductors + ground or Neutral in a single conduit?? I've never seen it Done???
HV ductbanks are derated by the number of conduits in the Ductbank not wires in the conduit.
Figure 310.60 Page 342 NFPA Code handbook.
70-159 NEC 2011


#213328 - 04/10/14 09:46 PM Re: 13.8 volts in conduit [Re: Yoopersup]  
gfretwell  Online Content


Member
Joined: Jul 2004
Posts: 9,136
Estero,Fl,usa
I am not sure why it would be prohibited but I think you pointed out why it is not attractive.

It sounds like you need engineering to determine ampacity.


Greg Fretwell

#213329 - 04/10/14 11:24 PM Re: 13.8 volts in conduit [Re: Yoopersup]  
Tesla  Offline
Member
Joined: Jun 2004
Posts: 1,273
Sacramento, CA
Purely hypothetical brain teasers are unworthy.

The better question is: At such power levels and cable sizes, when would it ever be economic to do so?

The swift answer is: Never.


Tesla

#213330 - 04/11/14 09:44 AM Re: 13.8 volts in conduit [Re: Yoopersup]  
Yoopersup  Offline
Member
Joined: Mar 2003
Posts: 835
Michigan
Tesla
Sorry not Hypothetical. Read Field problem.
Three 13.8 Switches single feed, Jumpers in between each (line side).
Load off each switch proposed to run thur same nipple as feed to switch! I don't make this stuff up I run into it!
Power calculations, Fill ect no problem.
Yoopersup

Nuff said.


#213331 - 04/11/14 10:39 AM Re: 13.8 volts in conduit [Re: Yoopersup]  
Yoopersup  Offline
Member
Joined: Mar 2003
Posts: 835
Michigan
Tesla
Sent you info on the E-mail you listed on here.
Codemanec


Page 1 of 2 1 2

Member Spotlight
electure
electure
Fullerton, CA USA
Posts: 4,262
Joined: December 2000
Show All Member Profiles 
Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.018s Queries: 16 (0.004s) Memory: 0.8178 MB (Peak: 0.9991 MB) Zlib enabled. Server Time: 2017-11-24 05:50:18 UTC