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#159599 - 01/08/05 03:48 PM More than 2 90's?
e57 Offline
Member
Registered: 05/27/03
Posts: 2876
Loc: S.F.,CA USA
Often, if we do not do the total install, we will get the winning bid for Electrical, which will often include some conduit for Tel/Data. So many of them have what I think is a far fetched interpitation of some of the telecom standards of pulling in conduit. i.e. The 2 90 rule... they wont pull in more than 180 degrees of bend, reguardless of fill.

So yesterday the Cablers show up, and I have to tell them the Arch would not allow extra pull boxes in some of the closed walls, and some of them have 3 90's His reply was, "We won't pull it! It damages the cable. And it's code." My reply, "What Code, I challenge you to find one." He only has 3 cat 5e cables in these 3/4" conduits, so I say, "Try some lube." His reply, "Oh, that damages the cable jackets too."

I have an idea where this comes from, an outdated TIA 568 standard (Not a Code) that was a little far fetched, and didn't differentiate fiber optic from copper cabling.

Just wondering if anyone had any thoughts on this?
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Mark Heller
"Well - I oughta....." -Jackie Gleason
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#159600 - 01/08/05 06:15 PM Re: More than 2 90's?
electure Offline


Member
Registered: 12/24/00
Posts: 4259
Loc: Fullerton, CA USA
Mark,
I'm not at all familiar with the standards, but can tell you that the 180° "dream world" predates the use of fiber optics.
I can remember hearing about it in '70.
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#159601 - 01/08/05 06:24 PM Re: More than 2 90's?
e57 Offline
Member
Registered: 05/27/03
Posts: 2876
Loc: S.F.,CA USA
Here I was thinking it was new.... I was born in '70!
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Mark Heller
"Well - I oughta....." -Jackie Gleason
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#159602 - 01/10/05 08:31 PM Re: More than 2 90's?
golf junkie Offline
Member
Registered: 04/22/01
Posts: 507
Loc: York, NE
I have seen this often in specs. but I've never seen anyone get bent about it.
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#159603 - 01/11/05 12:43 PM Re: More than 2 90's?
dstanford Offline
Member
Registered: 12/29/04
Posts: 23
Loc: Asheville NC USA
well i would rather not have alot of J-Boxes
in my big backbone and interduct pulls
you can always put another wrap on the tugger and use Lots of Lube.
sounds like pure lazyness to me
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#159604 - 01/11/05 06:34 PM Re: More than 2 90's?
golf junkie Offline
Member
Registered: 04/22/01
Posts: 507
Loc: York, NE
I would be interested to hear if anyone has actually ever damaged a cat 5 cable due to excess pull strain and under what conditions that occurred?
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#159605 - 01/11/05 07:07 PM Re: More than 2 90's?
SolarPowered Offline
Member
Registered: 07/05/04
Posts: 625
Loc: Palo Alto, CA, USA
Would you even know if you'd damaged it? You'd probably have to ping it out with a TDR to find out. With the error-recovery mechanisms built into comm protocols, the user likely isn't going to realize what's going on, either--he'll just have slower network performance than he would have had if there was no damage.
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#159606 - 01/11/05 08:40 PM Re: More than 2 90's?
e57 Offline
Member
Registered: 05/27/03
Posts: 2876
Loc: S.F.,CA USA
Graphic TDR it would still be realy difficult to tell I think, unless you printed out each pair before you pulled as a refferance. I'm sure someone with too much time on thier hands can cut to length test and install to check it again, like in some testing lab. However I can say that most Certification meters will test exactly the same before and after. (With the same termination.)

With pulling tension of 25lbs max, you could bundle a dozen or so and swing like Tarzan..... Kidding
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Mark Heller
"Well - I oughta....." -Jackie Gleason
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#159607 - 01/12/05 07:24 AM Re: More than 2 90's?
Radar Offline
Member
Registered: 04/30/04
Posts: 349
Loc: Los Angeles, CA
Here at the large public agency I work for in the Los Angeles area, when we award contracts for the installation of conduit to be used for data lines, we specify no more than 2-90's between openings. Nothing to do with code. Our IT techs who pull in the cabling later (fiber or cat-5) don't care if the openings are pull boxes or condulets, they just want easy pulling. Personally I don't think they have a tugger available, and wouldn't know how to use one (they aren't wiremen).

Radar
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#159608 - 01/12/05 08:59 AM Re: More than 2 90's?
hbiss Offline
Member
Registered: 12/16/03
Posts: 886
Loc: Hawthorne, NY USA
Don't think you would want to use a tugger with those cables.

Personally I think the "2 90" requirement is silly. I can't imagine how you could comply in many situations. No reason that you can't upsize the conduit and use a lubricant if necessary. Never heard of a lubricant damaging a cable by the way.

Maybe you need to rethink allowing IT techs with no experience doing this type of work.

-Hal
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www.myphonetechs.com
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