ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Whats a Better Coax For CCTV Applications

I'd concur with the comments so far: RG59 will be fine for baseband video over runs as short as those you're thinking about.

You can start getting problems with group delay over long distances, but you'd need a very much longer run of cable before that would start to become a problem.

Thanks for your responses. I'm also using 24 strand, 0.20mm (0.75mm2) figure 8. My runs will be about 40metres long and there will be five of them. Will i get voltage drop as the transformer will be that far away from the cameras? anybodys help would be much aprreciated.

Voltage drop won't be a problem...assuming a 24V supply. CCD cameras have low current requirements compared to their tube predecessors, so voltage drop is minimised to begin with. While I haven't actually checked it, the camera electronics presumably work on 12V so there's a lot of voltage drop you can get away with before regulation is lost.

I was going to use a 12V Supply, because the CCD Cameras are 12V. But if i use a 24V supply will i have overvoltage problems? What are your suggestions to use as a main supply 12V or 24V?

Britespark.
we do a hell of olot of CCTV installation work and we personally only use RG59 on shortish runs, and all cameras are on 12VDC.

the power supply units are fully rectified and regulated DC and are positioned as close to the camera as possible, but some installs we place the PSU by the main equipment and feed the camera via two core 1mm flex (under 100m) with no trouble or loss of picture quality.

all cameras are usually 480TVL and are fitted with Direct Drive lenses.

as to using Cat % or even Cat 6 this is not a problem, all you have to do is use a BalUn (Ballanced to Unballanced) connection unit to each camera and back art the Multiplex and or DVR (Digital Video Recorder.

the company we use is COP, details can be viewed on www.cop-eu.com

htey are very helpfull and have an excellent technical department, (and they are cheap, but very good quality equipment because they make it them selves!!)

if you need any advice just ask.

Britspark

thanks Britspark, your help is much appreciated. I so if put the Power supply near the main equipment and feed the cameras with 0.75mm2 Figure 8 i should have no problems. My runs will be less than 40 metres. Does this sound alright Britspark?

Britespark,
placing the PSU as close to the camera is recommended,

but it will not be a problem feeding the cameras from a central PSU with 0.75 2 core cable, just remember dont run it near 240/440v ac,

i have seen a few systems installed this way and the picture quality is a little funny!!

i have just quoted for a system, against the client supplying the kit and us fitting it, yes its a bit more expensive for us to supply and fit, but the client realises that you cant beat good quality cameras and good quality installation.

it all comes down to the old thing of `selection nand erection` of equipment.

oh and another thing, if you dont have one get one, a service monitor, a small colour lcd battery powered monitor. they are a godsend!! but they are not cheap, you should be able to pick one up from a dedicated security wholesaler, or use COP.

as before if you need any advice just ask.

Britspark

Britspark,
I've decided to buy the cameras and the DVR through COP Security. I'm gonna use RG6 standard for my coax runs, is there a problem running the RG6 near 240V AC?

What is the recommended distance away from 240V AC Power for the RG6 Coax?

Also what is the recommended distance away from 240V AC power for the 0.75 2 core flex?

Britespark.

if you are in the UK the regulation state that cat 1 and 2 cabling should not be run adjacent to cat 3 cabling anless there is continuous seperation.

the way we do it is either to put the coax in one conduit or trunking run and the power (12v) in another conduit

if the cameras are for external use you can ( obviously ) run the cabling adjacenmt to the existing 240v ac

basicaly if you run your coax and you 12vdc tgether in trunking you should be within the regulations.

try to keep all data (coax and 12v) away from any high loads IE motor / air con etc if you do run them near the above you will have a few ficture problems.

what DVR are you going for?

i have just ordered a 16 channel with LAN PTZ and CD/RW for a public house CCTV job.

going out tomorow to install a nice little 4 cameras ( colour day/night ) set up on a dry berthing site in town.
i am so looking forward to that job!!

Britspark

The mid-range day/night cameras that have infra red led illumination built into them pull quite a bit of current at 12 volts and are sensitive to volts drop. Their other problem is that the leds light up spiders building webs across the front of the camera!

Traditional style high end cameras still rule.