ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat
Recent Posts
Grounding electrodes
by gfretwell - 09/07/21 03:41 PM
Looking For Electricians in the Midlands
by Alex247 - 09/06/21 05:26 AM
Backup Generator Done Right
by timmp - 08/31/21 04:44 PM
New in the Gallery:
Now you know.
Now you know.
by Tom_Horne, September 7
February, North East Indiana
February, North East Indiana
by timmp, July 25
Who's Online Now
2 members (Scott35, gfretwell), 35 guests, and 14 robots.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
#213742 07/06/14 02:16 PM
Joined: Apr 2002
Posts: 189
T
triple Offline OP
Member
Am I correct that pvc conduit is allowed for essentially all low-volt conductors in a theater (according to 520.5(A) exception and handbook commentary)? Also, would pvc be among the code-compliant wiring methods for circuit and feeder conductors below a wood floor of an old theater? A wood floor obviously is not "fire rated construction". Purhaps the existing wood floor would not meet current building code?

2017 / 2014 NEC & Related Books and Study Guides
triple #213743 07/06/14 06:54 PM
Joined: Jun 2004
Posts: 1,273
T
Member
Theatres are SO touchy that you can't make your plans based upon the NEC.

You always need to touch base with the Fire Marshal.

The last theatre I worked on -- quite a while back -- the FM restricted PVC usage to below slab. The transition to EMT had to occur dang near flush with the slab.

PVC decays into cyanide gas and soot during partial combustion. Consequently many FM will not tolerate PVC since this result can be triggered by fires not started by the Low Voltage conductors.

Don't be surprised if plenum rated cables become necessary.


Tesla
triple #213744 07/06/14 07:09 PM
Joined: Apr 2002
Posts: 189
T
triple Offline OP
Member
In my personal opinion, pvc should not be allowed no matter what. However, the NEC , the NEC handbook, and a third-party handbook I have, all state that the rule does not directly apply to the communication, A/V, and fire alarm wiring. For these systems we are instructed to use their respected code articles. Those individual code articles simply say to use chapters 1-4 (specifically 3 of course). Obviously, different cities/municipalities can make up whatever rules they see fit. At present, I am only interested in national code. Thank you for your response Tesla.

triple #213748 07/06/14 10:11 PM
Joined: Jul 2004
Posts: 9,662
Likes: 4
G
Member
I agree with Tesla. In any "assembly" the fire code official is the king of the hill. You can meet the NEC and still not make them happy.


Greg Fretwell
triple #213750 07/06/14 10:53 PM
Joined: Apr 2002
Posts: 7,279
Likes: 3
Member
Agree with Tesla & Greg on the Fire Official.

Between the Building Codes and NFPA Fire Codes, any exposed PVC is not allowed. Products of combustion; flammability, flame spread, etc.


John
triple #213752 07/07/14 09:34 AM
Joined: Apr 2002
Posts: 189
T
triple Offline OP
Member
No conduit is exposed, pvc or otherwise.


Link Copied to Clipboard
Featured:

Tools for Electricians
Tools for Electricians
 

* * * * * * *

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

 

Member Spotlight
JoeKP
JoeKP
Berkley, MA
Posts: 144
Joined: March 2008
Top Posters(30 Days)
timmp 3
Popular Topics(Views)
282,898 Are you busy
216,663 Re: Forum
203,095 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.5