In the IDF/MDF rooms, I leave enough wire to reach the floor, plus a little extra (usually 10-14'). For feeds I leave close to double that - few things are more aggrivating to me than pulling 100pr cable through 3 floors only to find it's 10' too short and having to reorder and repull it. I pull enough wire to put in service loops, but I rarely find them there after the 66/110 block and patch panels are installed.
Last two jobs where I pulled enough coax for service loops, TWC used the length to go all the way across our backboard. :grr:
For boxes (wood stud buildings), I leave ~30" of wire in/out each on a prewire. Sometimes I've had to move a box over one stud either way, and that usually means rerunning home runs if there's only 12" of wire hanging out. 18" of wire X 500 drops does add up, but is dwarfed by the cost of opening up a finished wall to properly terminate a short wire or a box that has to be moved.
If it's in conduit, I leave enough in the box to trim out three times (~18" cat-whatever, 10" coax)
CCTV and access point drops get plenty of extra wire (~20') if they are in accessable ceilings - too many times I've seen the owner change his mind on cameras ("I want it here, not there...), or access points have a small lapse in coverage that can be rectified by moving them a little bit.
'course, Hilton is going to have their IT guys put a 7' patch cord on their WAPs no matter how much extra wire I leave them. :bang:
I leave plenty for sound drops as well, since lobby and other 1st floor ceiling plans often have a way of getting changed w/o me knowing. It's kinda hard to mount a speaker inside of a light fixture.
I also place a small service loop (a foot or so) out of conduit stubs above drop ceilings, logic being that *if* a splice has to be made, there is wire with which to work, and that if the wire is yanked, the loop will come undone rather than the cable getting stretched or yanked out of the box.
Jeff: one wire cut to 10"? I'd kill to have that drywall crew if that was their only mistake. I've had to buy additional tools to trim coax due to about 3" of good wire sticking out of the box (good ol' Rotozip). I hate Scotchlocks, but I've used more than I care to admit.
Sorry for this ridiculously long post re: service loops - I just really dislike working with short wires and doing things twice. I like to make sure the next man can do his job, especially since I'm often the next man.
I'd more than appreciate any feedback (good or bad) on the above practices.
