FIBER RUNS

[Jhaney]

What limits the service loop to a maximum of 100'?

Someone high up in AT&T saying 100 feet max, you know the guy who knows everything but has done nothing. But in all honesty splice points should be at a location as far away from the previous splice as possible and have very easy access so extra lenght in the service loop shouldn't be necessary. In most cases the loops I design are only 50 feet on either side of the splice. They have recently decided that maintenance loops (loops at a dead end pole that may be changed out) have to be 30 feet period.

 

[Bfksiazek]

splice loss

splice loss

Normally in a fusion spice you lose about .20 db and in a joined pair your looking at .75 db

 

[Alwayslearningelec]

When ordering fiber I get the actual length of the run estimated as close as possible, add double the length of the termination room for each end, and then add 10%. I will NEVER get to the end and not have enough. An FOA certified installer will tell you that this IS the way to estimate your length, because at the termination points, you can very easily run out of slack, which would never be acceptable.

In addition, as a termination practice, any slack (waste as you seemed to imply) will be coiled very loosely, but in a neat, and workmanlike manner in spaces provided for that purpose just above or inside the actual termination point. Fiber cables are not cut "exactly to length."

Also, a comment about splicing: if the splice is not specified in the drawings, and an installer just added one somewhere, even with the appropriate protections in place, the cable would be reordered and pulled again without the splice on the jobs I've worked.

So if you are landing the fiber in two separate control rooms that are say 20' length you would add 40' +40' and them 10%?

 

[iMuse97]

So if you are landing the fiber in two separate control rooms that are say 20' length you would add 40' +40' and them 10%?

Yes. This will give you the amt to order for the room itself.

 

[quogueelectric]

Ensure sufficient slack

Ensure sufficient slack

So is this how the phone company/cable TV guys have enough wire to reach their truck/trailer

where they do their work ?

According to Corning General consideration s for slack. Splicing and termination points. Sufficient slack to reach a good splicing environment.---Future relocation of termination ...Enough slack to reach all logical nearby locations; the rack/hardware may move in the future. -----Mistakes Fiber breakage at end of cable jacket...Kinking of cable at closure entry point....-------Cable damage....Assume worst case accident...Ensure sufficient slack to re splice / re terminate in the same location if possible. They then go on to say for example out of a manhole long enough to reach your truck with splicing equipment out of the manhole plus 15 meters / extra slack to be neatly coiled back in the manhole after splicing.