Measuring cable

[OMaraSTO]

Hi all, this should be a nice easy one for ya...

What is the best quick & easy way to measure cable from a reel?
For example, I have a boxed reel of Cat5 cable, and someone comes along and asks me to make an eight metre long cable, what's a good rule of thumb (I don't want to reach for a tape measure every time!)

Also, for longer runs (using solid cable) eg. I sometimes have to run cables from one portacabin, underneath about another two portacabins, and up through the floor of another portacabin, what is the best way of estimating how much cable to cut off to do the run??

Any input is much appreciated.

Steve

 

[Bobg1]

Look at the cable you are useing, there is a good chance that there are measurements marked on the jacket.
Another rough estimate, measure your arm span and when you are pulling the cable from hand to hand you have a good idea how long.
As for running cable, you should be pulling it off the spool and not cutting it to length until you have it where you need it.

 

[mikeydidit]

If the cable is not marked with the foot markings on it there is another way I use. I have layin type tiles on the floor of my equipment room and in the halls. Count the tiles as you pull out your cable. Each tile is exactly 1 foot by 1 foot. Also look above you. Each layin ceiling tile is either 2x2 or 2 x4.


Mikey

 

[DTSMAN]

I pull multiple runs from one box too. I estimate my length and pace it off as I pull from the box. Get your tape measure out fully extend it to 25 or 30 feet and pace it off, and when you pull from the box count your steps. Now you will have a rough idea of how much to pull out. Of course this gereates waste but what do you do. You could setup 4 or 5 boxes and pull them all at the same time to try and save. When I pull from the box my count is 2,4,6,8,etc as I step plus some for extra. Thats my method.
I look at a wall to go up a say 10ft, down this hall 60ft and over this office 12ft. Add it up and give yourself some extra for service loops and cut the appropriate number of cable lengths that follow that path.
As bobg1 said for short cables use the markings on the cable.

 

[OMaraSTO]

Thanks guys, some interesting thoughts so far.

I only just noticed that my solid Cat5 does have the time & date & distance stamped on it at 1 metre intervals, so that's useful. I'm totally puzzled though, because my stranded cat5 doesn't yet it's in a virtually identical box and made by the same company!!
As for pulling the cable off the spool, my scenario is usually to run about 4 cables from one spot at one end of a cabin, to one spot at the other end, so it's much easier to run the four at once rather than one at a time off the spool.
For similar resons, mikey's ideas are great, but impractical for my situation as our cabins have plain vinyl floors and plain ceilings.

Any more ideas?

Thanks

Steve

 

[ANFPS26]

Measure the floor from the reel and put a piece of tape on the floor at, say 25 meters, then you only have to measure once. If the length should be 50 meters then double the cable back and so on. We used to mark the floor with tape at 5 foot increments if we were running different lengths.

Jim

 

[Mongo5150]

Get a tester that gives you length, if you dont already. Test cable then get the length.

 

[abscomm]

Stranded CAT 5 cable is for patch cables, solid CAT 5 is for wiring runs, it is usually not necessary to make extremely long patch cables so footage markers are not needed.

 

[ttech]

Count the floor or ceiling Tiles if the are there.

-Don

 

[buitenhek]

abscomm is right on with solid and stranded cable. In addition, stranded cable requires different RJ45 jack grips. The solid cable punchdown has a pinch design (IDC-insulation displacement conductor) and the stranded punchdown has a pinch & lock design to keep the stranded cables from shifting in the grip.

Also, I am unsure how a fire marshal would interpret your cabin-to-cabin arrangement, but are you required to place the cable in a conduit between cabins and seal the conduit for fire protection? Which brings plenum and PVC issues also into place. If there is a fire and someone does get hurt, a lawyer loves to prove you provided a flame-wick between cabins.


Regards,
Peter Buitenhek
peter@profitdeveloper.com

 

[Jd925]

As for the fire issue i found a spray that makes what you spray fire retardent i ran a cable under 2 portable office trailers and they did not like that. Same as all other utilities there had to be a drop for each anyway i ran the wire and sprayed it. I want to try the stuff out. So i ran a cable and hung it between 2 sticks and sprayed it on left it there for a week. It rained twice that week and on friday i came back. It did not ignite. So it seemed to work prety good.

 

[ANFPS26]

If you use the proper cable in the proper application spraying is not necessary. In a very hot fire the spray is useless and the cable would still be toxic.

Jim

 

[Jd925]

Its just a temp run it is not staying there and that can get expensive