ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Top Posters(30 Days)
dsk 13
Admin 4
Recent Posts
electircal ageing test on IPC
by SIAME. 08/15/17 02:43 AM
electrical aging test on IPC
by gfretwell. 08/15/17 12:27 AM
Bathroom electrical
by gfretwell. 08/14/17 02:05 AM
"Line level" audio on Cat 5?
by gfretwell. 08/08/17 10:39 PM
Fire alarm phone lines and color coding
by gfretwell. 08/08/17 10:26 PM
New in the Gallery:
Housebilding DIY wiring
Popular Topics(Views)
239,877 Are you busy
175,443 Re: Forum
167,727 Need opinion
Who's Online Now
0 registered members (), 44 guests, and 9 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate This Thread
Page 1 of 2 1 2
#186532 - 05/18/09 02:17 PM 1-hour fire rated conduit?  
SteveFehr  Offline
Member
Joined: Mar 2005
Posts: 1,208
Chesapeake, VA
NEC Article 708.10(C) requires critical feeder circuits to be in RMC/IMC and have a 1-hour fire rating. I can't say I've ever seen such a beast. Are they sold commercially? What do they look like? I've got this mental image of putting pipe lagging on conduit, but I'm not so sure that would be enough. Do we have to start building insulated drywall boxes around conduit runs?

... and then 708.14 requires the same for thermostat wiring, phone wire and pretty much all critical communications circuits. I don't think those guys are going to be happy when their cable tray becomes drywall-encased RMC.

- before anyone gets too excited, 708 is "Critical Operations Power Systems", new in NEC 2008, and only applies to homeland security/military/emergency services type stuff.


Work Gear for Electricians and the Trades

#186533 - 05/18/09 03:07 PM Re: 1-hour fire rated conduit? [Re: SteveFehr]  
ghost307  Offline
Member
Joined: May 2005
Posts: 907
Chicago Illinois USA


Ghost307

#186554 - 05/19/09 08:32 AM Re: 1-hour fire rated conduit? [Re: ghost307]  
SteveFehr  Offline
Member
Joined: Mar 2005
Posts: 1,208
Chesapeake, VA
Wow, at $20-$50/square foot, that stuff is insane; at $25/ft2, it would add $30/ft to 4" RMC in material alone, and probably is a real pain in the ass to install, too.

It's rather unique, though, in that it's thin when applied and expands. Most article 708 applications aren't going to be that tight. There's got to be someething reasonable out there?


#186560 - 05/19/09 10:49 AM Re: 1-hour fire rated conduit? [Re: SteveFehr]  
ghost307  Offline
Member
Joined: May 2005
Posts: 907
Chicago Illinois USA
It's definitely an expensive option, especially when you see that you need to follow the installation instructions to the letter; including the special stainless steel tywraps.

I specified it once when there was "no physical way" to get a rating on a conduit run in a hospital. It was interesting to see how it went from "no physical way" to "OMG, this costs HOW MUCH???" to a field verified reroute that allowed the conduit path to be under the slab via a sawcut trench.
This stuff was originally designed for the nuclear power folks where the conduits needed to be fire-rated pretty much everywhere.

Why protect everything in sight? If you had a fire you didn't want to wipe out the safety, control, alarm, emergency functions all at the same time.


But back to your question; is there a way that you can create a big conduit chase and route most of the runs through it? Even if it means that some of the runs will be taking a longer path it might work out cheaper and easier in the long run. Unless your AHJ raises an objection, I don't see a requirement that the conduits need to be separated from each other, just from the potential fire/disaster.


Ghost307

#186586 - 05/20/09 08:29 AM Re: 1-hour fire rated conduit? [Re: ghost307]  
SteveFehr  Offline
Member
Joined: Mar 2005
Posts: 1,208
Chesapeake, VA
Building an insulated drywall chase around the conduit is certainly *a* option, but I was hoping for better options. Interferences in tightly packed overhead spaces make building a chase like that very difficult, and difficult to work around in the future, too. Considering the wording of NEC and the lack of real listed products at this point, it might be the only viable option, though.

There's no simple fiberglass wrap or anything like that out there that offers sufficient insulation?


#186593 - 05/20/09 10:46 AM Re: 1-hour fire rated conduit? [Re: SteveFehr]  
ghost307  Offline
Member
Joined: May 2005
Posts: 907
Chicago Illinois USA
Not that I'm aware of. I can't find anything in the UL book either.
My guess is that if there was a cheaper way to wrap the conduits, nobody would buy the Flameseal stuff.

Maybe someone else on the forum knows of another UL Listed product.

This is why I see a major impact fron NEC 708. When the building is initially designed there should be a way to route everything in a protected manner. Unfortunately, it's more likely that the Architects will design their usual pretty building and say that compliance is "someone else's problem". In a somewhat similar situation at Chicago's McCormick Place, there were drywall chases built in a lot of the corridors just to address the routing of some of the critical systems...big mess, but it worked out in the end.
smile


Ghost307

#186597 - 05/20/09 01:17 PM Re: 1-hour fire rated conduit? [Re: ghost307]  
SteveFehr  Offline
Member
Joined: Mar 2005
Posts: 1,208
Chesapeake, VA
I had to break it to the network guys that their favorite orange smurf tube and cable tray had just been outlawed by 708.14, and that they'd better start stocking up on RMC and insulation.

What many others reading this thread probably don't realize is that anyone who has so much as an optional backup generator for "business continuity" (Wal-Mart, gas stations, Mom & Pop's corner store, etc.) is now required to abide by these rules, too, 708.2 says so. I predict some large changes in Article 708 in 2011. Gonna be a lot of new drywall chases installed in wal-marts and grocery stores throughought the nation if this is enforcedd.

I want to track down the US Army guy who submitted all this stuff (I recognize a lot of the wording from some Army tech specs)...




...and when I finally find him...





...see if I can get some of his budget! He's obviously way better funded than I am wink


#186599 - 05/20/09 03:21 PM Re: 1-hour fire rated conduit? [Re: SteveFehr]  
ghost307  Offline
Member
Joined: May 2005
Posts: 907
Chicago Illinois USA
I don't think we'll see many Walmarts following 708. When this was covered in our IAEI section before it came out in the 2008 NEC, it was applicable to facilities that had been singled out by some government agency (like Civil Defense).
That way the systems in truely critical places like (maybe) 911 Call Centers would be designed to be protected per 780, but not every place would be hit with the expense.

I could foresee a Walmart being a place to house those chased out by a flood, but not a place where major rescue operations would necessarily be headquartered.

BTW, I really don't want to tell the IT guys about the orange smurf tube; I'd rather laugh histerically when they do their own work with a flashlight and standing on a chair...then have to rip it all out because they don't have a CLUE what they're doing.
Remember that old P.T. Barnum quote "Never smarten up a chump".
wink


Ghost307

#186603 - 05/20/09 08:19 PM Re: 1-hour fire rated conduit? [Re: ghost307]  
renosteinke  Offline
Cat Servant
Member
Joined: Jan 2005
Posts: 5,316
Blue Collar Country
Wal-Mart a COPS site? I think not! Period. Such an understanding of 'critical' borders on the absurd.

Looking at the NFPA's "Analysis of Changes," thay give, as examples of 'critical' operations, such places as 911 call centers and fire stations - not your local discounter.

Though, to be fair, the "Analysis" does mention Hurricaine Katrina, and we just couldn't have folks looting Wal-mart in the dark, could we?

The "Analysis closes by referring to :maintaining continuity ..... for critical operations." Let's focus on that adjective: critical. Let's not confuse it with 'nice,' or 'desireable,' or even 'necessary.' The word is "critical."

To use an analogy: in a fighter jet, wings and engines are necessary .... but the parachute is critical. As far as I'm concerned, the NFPA paints with far too broad a brush when they claim data-processing centers and mass transit systems are good examples of 'critical operations.'

That's what it comes down to .... the 'enhanced' protections are considered as required only under extreme circumstances. Just because battleships have 16" of armor plating does not mean that the local game warden needs that on his bass boat.

Though, from my own perch within some government entities, it does seem that every 'governing body' has seized on their governmental status as reason to madly over-design and over-spend .... using things like 708 as justification. Heck, when it comes to spending, they're on a mission .....



#186606 - 05/20/09 09:05 PM Re: 1-hour fire rated conduit? [Re: renosteinke]  
sparky  Offline
Member
Joined: Oct 2000
Posts: 5,311
so we're trading in our old 'wire for fire' tradespeak for 'wire for terrorism'now?

~S~


Page 1 of 2 1 2

Member Spotlight
Niko
Niko
Campbell, CA
Posts: 356
Joined: August 2006
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: 0.024s Queries: 16 (0.004s) Memory: 0.8223 MB (Peak: 1.0045 MB) Zlib enabled. Server Time: 2017-08-17 17:35:55 UTC