Iam thinking of changing to cat 5 cable of the four pairs of cable can i use one pair for video one pair for power two pairs for motorised lens?

Yes, I have used for PTZ cameras using one pair for video, one pair for PTZ control and two pair for power. Hope this helps. :)

How longs the run

You'll need a balun at each end for the video,
You might want higher rated cable (prolly multistrand also) for the power,

I wouldn't rely on the cat5 for my power, but all the rest is fine,
double up the power if you really have to - 2 pairs pwr, 1 pair vid, 1 pair ptz/lense...

What was the power type on the camera?

ya it certainly depends on what power is trnsfered tohro cables....if it is 110V someting ( Mains power) certainly not recomanded ...will spoil your image....ang some how if cable breaks .......system may burn!!!! :D

...but definitely worth finding out. I'd use CAT6E cabling. You'll get a longer run out of it and it will hold power better. Baluns at one or both ends.

You won't get a longer run out of CAT6E. Voltage drop on it will be the same as CAT5. You will get less cross talk which might get you a slightly better signal at the same distances but it's not going to be radically further and not worth the extra cost.

The difference between CAT6 and CAT5 is just the cross talk between pairs. This allows for higher speeds for data transmission. It does not extend the broadcast distance at all.

true!! altering cat5 to cat6 doesn't make any diffrence in terms of voltage rationgs tranfered

It's true if you just go by the published Cat 6 specifications. But if you look at the manufacturers specs you will find many manufacturers use 23 gauge conductors instead of 24 in their CAT6.

In most applications that probably doesn't make a big difference; But the bigger gauge wire does translate to less voltage drop. That could make a difference in some installs.

It's true. Assuming you have a 12VDC camera that draws 150mA:
A 24 gauge power wire can be run approximately 156 ft.
A 23 gauge power wire can be run approximately 196 ft.
A 22 gauge power wire can be run approximately 248 ft.

Here's a link to a wire length calculator http://www.video-insight.com/Support/Tools/Wire-Length-Calculator.aspx

Power on the PTZ is 24vac, and I still have that camera running that way, thats my mini dome that I have been testing for so long. :D

If it is 24 V ac then it's ok....
no problem dear!!!

I also utilised such spare cables while no chose left behind during maintainanace of some old dirty installations.......... :D

if it is cabling phase of the project......recommanding higher gause cable!!

Just do it !! Good luck....

Kalpesh Nikumbh

India :)

What is the twist rate per inch for cat6 compared to cat5?

If there is more twists in the wire, then the overall length will be longer than the length of the equivalent cat5 cable...... (Come to think of it, how much extra length do the twists add on a cable run??)

cat 6 has varying twist ratios between pairs. The idea is to ensure that no two pairs have exactly the same twist ratio at any point in the cable run in order to minimise crosstalk.

Wait, you're running alternating current on unshielded pairs next to the video pairs? And this works without lots of interference?

Have been for quite some time, have been testing the mini ptz this way and no noise or interference at all, even have a new 35x ptz testing the same way and no interference at all. :D

I will have to pull a certified test and look. It shows the different length of the pairs in a single cable. But from what I remember a 100+ ft run of 5e all the pairs were within 1 or 2 percent of each other. The difference in length is the varied twist rate from what I can tell.

Next time I'm thinking of it I will check the test result length compared to the cable jacket marker...



Edit:

here's what I show on a random test result:

Superior Essex 5e

pair 1 (4,5) 107'
pair 2 (1,2) 104'
pair 3 (3,6) 108'
pair 4 (7,8) 105'

it labels the cable as 104'

Thanks for all your help on my Cat 5 question .
The next Question i have does it matter which colours i use for Camera
/Power/Motorised lens the cameras i use are 12v . What i am trying to do is to use one pair for power one pair for the camera and two pairs to a rocker switch so i can control the lens .Any thoughts would be a great help as you chaps are the experts :D

You are not going to get any distance on 12vdc, will have to keep your power close to the camera or make sure you have a power supply that gives you 12vdc at the camera.