ECN Forum Forums General Topics of the Trade Voice - Data - Video Discussion More than 2 90's?

I agree, maybe the IT Guys should first learn the trade and then buy the tools to do it(fishtape). at my company we can even
run the conduit if need be and we can put up to 4 90's between boxs. but we try to leave that for the big burly electricans to do :-)

I am almost 100% sure (>96.90023417%) that I have seen an IBM Specification note regarding 180° Maximum, for scenarios involving Conduit runs and pulling in Type 1/2 STP Cables.

Of course, this was back in the 1980's (the terminology of Type 1/2 should date its self!).

Let me dig up some of the legacy documents to see what's up.

As far as anything modern (>1995 A.D.), I had been given the 180° Maximum specification on the first FDDI Backbone Install I ever dealt with - circa 1999 to 2000.
Technology of the Cable was likely the reasons for the Paranoia - and this Backbone's Conduit Runs were filled with Pullboxes!

Ran from/to/between NERs on 3rd, 6th and 9th Floors.

Outside of the loops involved with the Pullboxes, the Cable Pulls were extremely easy!
(1 Fiber Optical Cable in an 1¼" Conduit tends to be somewhat easy to pull - even without Aqua Gel!).
The same cannot be said about the actual EMT / Pullbox installations!
That's where the "fun part" came into play!


Scott35

Here's more. http://www.mikeholt.com/codeforum/ultimatebb.php?ubb=get_topic;f=9;t=000252

The 2 90% bends come from BICSI organazation, a telecommunication standard writing organazation. It is not associated with NFPA nor can it be enforced by an AHJ. The only way to enforce the requirements are by contract specifications.

I had that spec at a large popular theme park a few years back. I had a 4” run between the main telecomm. Room and a remote room (they did not refer to it as an IDF). It was a retail space with themed rooms through out. In order to miss the plumber, fit inside the building and comply with structural specs (like angle of oppose) I had to put 3, that’s right,3 90’s in the run!!! I decided to take a chance rather than write the RFI requesting a 3X5 concrete pull box inside there retail space (with the fancy custom concrete floors). I never heard any complaints about tough pulls from the data contractor. I am sure it will be fine for years to come. I think the 2 90 requirement is just an easy way to assure easy pulling. What is wrong with doing the pull calcs to prove <25lbs.??

I used to work for a contractor in the NYC area and we did all our own conduit work, my employer never specified anything about no more than 2 90's in a run and we sometimes ran up to 16 cables through a 1" emt with 3 sometimes 4 90's in the run (we definitely pulled pretty hard with plenty of lube) and we never had a line fail for any reason other than a swapped pair or bad jack.We subjected these lines to testing using our Fluke OmniScanner2 which tests for all of the specifications set forth by the T568B? standard.I from first hand experience have definitely got to say that this spec of no more than 2 90's in a run of conduit is got to be for ease of pulling.

I forgot to mention that it was a tel\data contractor that I worked for.

The only thing they have you on is not installed to spec. If it is speced for no more than 2 90's then what can you do. Kind of sucks but at least there are no wires in it so a can could be cut in easy enough.