Tek-Tips is the largest IT community on the Internet today!
Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!
-
Congratulations strongm on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!
Why can't I run underground cable inside our building's cielings? 4
- Thread starter Snapper
- Start date
-
1
- #2
-
1
- #3
There are several variables.
If this is a suspended ceiling more than likeley the space above is used as a plenum for air movement. In which case plenum cable is required. Plenum cable has a different jacket that emits less smoke and toxic fumes in case it is exposed to fire.
I'm not sure why you would want to use UG cable when you don't have to. Plenum is still a lot easier to work with.
If this is a suspended ceiling more than likeley the space above is used as a plenum for air movement. In which case plenum cable is required. Plenum cable has a different jacket that emits less smoke and toxic fumes in case it is exposed to fire.
I'm not sure why you would want to use UG cable when you don't have to. Plenum is still a lot easier to work with.
- Thread starter
- #4
-
1
- #5
AvayaNovice
Vendor
Plenum cable is ONLY needed in suspended cielings in which a return air system is used. What that means is that air flow is brought through the cieling. I only see that in about a quarter of the buildings I've worked in.
Underground cable being used in the cieling doesn't really make any difference. It's heavier, not by much... it's usually filled with a gel that makes it gross to work with, and it's not as easy to work with as indoor rated cable, but whatever works -- works.
Underground cable being used in the cieling doesn't really make any difference. It's heavier, not by much... it's usually filled with a gel that makes it gross to work with, and it's not as easy to work with as indoor rated cable, but whatever works -- works.
mikeydidit
IS-IT--Management
If it is a PE or jelly filled type cable it cannot be extended passed 50' from the outside entrance unless it is installed in conduit. I beleive this is in the 568a commercial buildngs codes and standards. This is like Bobg1 stated that it does emit smoke and toxic fumes.
If you find any mistakes, please consider that they are there for a purpose. And everyone needs a purpose.
Mikey
If you find any mistakes, please consider that they are there for a purpose. And everyone needs a purpose.
Mikey
-
1
- #7
daronwilson
Vendor
Uh....No, it is NOT ok. According to the National Electrical Code, cabling installed in buildings must be rated for the enviornment it is in (CM, CMR, CMP, etc for communications cables.
PE type cables for outdoor use are NOT rated, and as such are illegal to run iside the structure. The electrical code allows you to use this building entrance cable to feed service into the building provided you do not run it more than 50' inside the building and ground the sheath as close as practical to the entrance point. You may run the cable farther than 50' (at least for entrance cable) IF you encase it in rigid metal conduit all the way to the backboard where it is terminated, grounded and protected.
Good Luck!
It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com
PE type cables for outdoor use are NOT rated, and as such are illegal to run iside the structure. The electrical code allows you to use this building entrance cable to feed service into the building provided you do not run it more than 50' inside the building and ground the sheath as close as practical to the entrance point. You may run the cable farther than 50' (at least for entrance cable) IF you encase it in rigid metal conduit all the way to the backboard where it is terminated, grounded and protected.
Good Luck!
It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com
AvayaNovice
Vendor
Good point. I guess reason for that being is that it can carry something over the metal sheath...
daronwilson
Vendor
The main reason explained to me is they have no flame rating on the jacket, and i believe no flame rating on the gel filler either. To have a cable listed for indoor use, the manufacturer has to have the cable tested and it has to meet specific requirements for flame spread and toxic byproduct production.
There are indoor/outdoor fiber products that are black PVC jacketed AND rated, but I've not seen this in telephone wire.
Your point on Plenum is well taken, the majority of the suspended ceilings are not air handling spaces, but merely a ceiling to hide the air handling ducts. However, check your local and specialty codes as well. Many specific occupancies require plenum regardless, and many jurisdictions require plenum regardless as well.
Good Luck!
It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com
There are indoor/outdoor fiber products that are black PVC jacketed AND rated, but I've not seen this in telephone wire.
Your point on Plenum is well taken, the majority of the suspended ceilings are not air handling spaces, but merely a ceiling to hide the air handling ducts. However, check your local and specialty codes as well. Many specific occupancies require plenum regardless, and many jurisdictions require plenum regardless as well.
Good Luck!
It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com
I was just told by Graybar that there is a outdoor cable that can be used indoors and is rated for indoor use. The cable does NOT have any jell filling and is primarly used indoors for warehouse applications.
I love it when I learn something new!
Thanks guys!!
I love it when I learn something new!
Thanks guys!!
daronwilson
Vendor
Did he tell you what it was? There is an outdoor 4 pair CM type wire that is rated, we use it stapling on the outside of houses.
I guess I view outdoor wire as direct burial type, always gel filled, PE type cable. We don't put anything in the ground that isnt filled here at the coast, it just wont survive.
So...share the wealth! What cable was it?
It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com
I guess I view outdoor wire as direct burial type, always gel filled, PE type cable. We don't put anything in the ground that isnt filled here at the coast, it just wont survive.
So...share the wealth! What cable was it?
It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com
daronwilson
Vendor
Hmm, I'd be very curious, we could sure use it in some applications. I'll call my saleslady at Graybar and see if she knows of it.
thanks
It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com
thanks
It is only my opinion, based on my experience and education...I am always willing to learn, educate me!
Daron J. Wilson, RCDD
daron.wilson@lhmorris.com
The biggest probem I see is hauling in enough dirt to cover everything......."pa-dah-dump"
Thank you, thank you, Ill be here all week......
Really tho, Dont see anything but a problem with the cable....Code is there for a reason....
Besides....I HATE THAT GELL!!!!!!
Do it right, get the right cables, we have enough headaches without the inspectors fussing.....then again, while we are hauling the dirt.......
Randy
Thank you, thank you, Ill be here all week......
Really tho, Dont see anything but a problem with the cable....Code is there for a reason....
Besides....I HATE THAT GELL!!!!!!
Do it right, get the right cables, we have enough headaches without the inspectors fussing.....then again, while we are hauling the dirt.......
Randy
- Status