ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
Potseal 10
Recent Posts
Old decora style outlets
by Lostazhell. 04/22/17 07:59 PM
Dimmable LED 2x4 lay in fixtures
by gfretwell. 04/22/17 01:14 PM
Permit Snafus...AHJs and Contractors Jump in
by gfretwell. 04/22/17 01:11 PM
How do you find a good employee?
by HotLine1. 04/22/17 10:44 AM
Electrode boilers question
by SteveFehr. 04/21/17 08:32 AM
New in the Gallery:
SE cable question
Popular Topics(Views)
234,488 Are you busy
169,150 Re: Forum
162,497 Need opinion
Who's Online Now
0 registered members (), 62 guests, and 7 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
Page 1 of 2 1 2
#25128 - 04/26/03 09:45 AM Support M/C  
Obsaleet  Offline
Member
Joined: Apr 2003
Posts: 362
Pa
How do you feel about using tie wraps to hold M/C cable above a drop ceiling? How about in a Plemun?


Ob


Choose your customers, don't let them choose you.

Work Gear for Electricians and the Trades

#25129 - 04/26/03 11:21 PM Re: Support M/C  
golf junkie  Offline
Member
Joined: Apr 2001
Posts: 507
York, NE
It's fine with me as long as the AHJ will allow it. Some will some won't.

GJ


#25130 - 04/27/03 10:40 AM Re: Support M/C  
NJwirenut  Offline
Member
Joined: Sep 2001
Posts: 806
Bergen County, NJ
In a plenum, the AHJ will (should) require plenum rated cable ties.


#25131 - 04/27/03 10:52 AM Re: Support M/C  
Obsaleet  Offline
Member
Joined: Apr 2003
Posts: 362
Pa
Yes Nj I thought about that. I have yet see them plenum rated. [Linked Image]I have been using the batt ears. I am trying to get a opinion about this. My other thought is that the perpose of these things is to keep the cable off the firepeople. Tiewraps aren't going to cut it.


Choose your customers, don't let them choose you.

#25132 - 04/27/03 12:22 PM Re: Support M/C  
resqcapt19  Offline
Member
Joined: Nov 2000
Posts: 2,148
IL
Obsaleet,
Even if the wire ties fail in the heat of a fire, the cable will not fall on the firefighters unless the grid itself has also failed.
don


Don(resqcapt19)

#25133 - 04/27/03 12:55 PM Re: Support M/C  
Cindy  Offline
Member
Joined: Jun 2001
Posts: 196
PDX, OR, US
all of 300.11 talks about support 'wires' and 300.11a1, fire-rated, says to tag the slack wires...

so i thot the idea of independent supports was to allow the electrical equipment to stay up there if the tiles and grid are dropped. limited energy guys use ties up there all the time, plenum rated if plenums, but we use the 12gage aircraft cable for our line voltage to support everything. and even though the MC section says you dont need support for the whips, we use them based on 300.11A, last sentence.

do fireguys cut the grid loose to drop it? is that the reason for tagging them?
anyway, my vote is to use the slack wires vs tie wraps


#25134 - 04/27/03 02:52 PM Re: Support M/C  
Obsaleet  Offline
Member
Joined: Apr 2003
Posts: 362
Pa
Cindy,
I was told this in 2 code classes. "when the fire people comeinto the building they use there poles to pull down the ceiling".
I have been told by firemen that they don't do this in practice. At least not in our local.


Choose your customers, don't let them choose you.

#25135 - 04/27/03 04:26 PM Re: Support M/C  
NJwirenut  Offline
Member
Joined: Sep 2001
Posts: 806
Bergen County, NJ
Plenum rated cable ties are widely available from the usual suppliers (Thomas and Betts, Panduit, Tyton, etc.). A good deal more expensive than the usual nylon ones, though.

One source:
http://www.connectworld.net/bulkcable/bundle_secure11.html


#25136 - 04/28/03 02:24 PM Re: Support M/C  
kale  Offline
Member
Joined: Nov 2002
Posts: 174
You can usually find Stainless Steel cable ties for less money than the plenum rated plastic versions.

The stainless ones would satisfy the requirements listed here.

BTW, Panduit's plenum ones are purple in color to help you recognize them.


#25137 - 04/28/03 03:39 PM Re: Support M/C  
resqcapt19  Offline
Member
Joined: Nov 2000
Posts: 2,148
IL
Firefighters will often "open" ceiling to check for fire spread or to apply water. With a grid ceiling they will not attempt to pull the grid down, but only pull down the tiles. The grid falling around them creates the very real possibility of entanglement and is not something that would be done intentionally.
The reason for the "identified" supports in a fire rated ceiling has to do with the rating of the ceiling. There are very specific construction rules for fire rated ceiling assemblies. The only reason for the identification of the electrical support wires is to make it easier for the building/ fire inspector to verify the fire rated ceiling assembly has been correctly constructed. The fire rated ceiling assembly design does not include the support of anything other than the ceiling itself. The support of electrical conduits or cables using the fire rated ceiling support wires would void the fire rating of the ceiling.
Don


Don(resqcapt19)

Page 1 of 2 1 2

Member Spotlight
Posts: 165
Joined: March 2007
Show All Member Profiles 
Featured:

2017 NEC and Related
2017 NEC
Now Available!

Shout Box
Powered by UBB.threads™ PHP Forum Software 7.6.0
Page Time: 0.016s Queries: 15 (0.004s) Memory: 0.8150 MB (Peak: 0.9908 MB) Zlib enabled. Server Time: 2017-04-23 17:54:33 UTC