Hi Guys,
we have a 14 camera system installed at clients offices. 3 of the 14 internal cameras (dome infrared) are giving a black & white image half way through the day.

If i power them off then on, the problem goes away but seems to come back after a few hours?

2 of the cameras are on 40 metres runs and the other is on a 20 metres run all over cat5e with passive video baluns on both ends? Using a 10amp 16 way 12v power supply unit. (Am I overusing the maximum 10amps???)

anyone come accross any problems such as this? any advice on what i could look at?? I'm due to go back to site on thursday so would not mine some advice on what I could try.

Thanks

Sounds like voltage drop issue, not enough power at 40 meters to sustain the camera's. Hope this helps.

Whats the current rating of each camera, as if you have 14 cams on a 10amp 16 output supply thats a max of 710ma ish per camera, you may well be pushing that power supply a bit hard (but depends on how much current they need with the IR on, should be stated in the manual). Plus the problem with voltage drop as mentioned.....

Hi guys thanks for your replies, I went back today and using a multimeter I checked the voltage at camera end and it was 12v no drops for the period I was there.

I have done two things today, 1st thing was to change the camera on one of them, and then I used a 12v wall adapter to power the other. I was just curious to see if any of these changes would make a difference. If either one does I may have cracked it.

Weired thing is when I unplug the bnc from the dvr end and then reconnect the picture is fine again. But then ater a few hours the picture goes mono again. I am starting to think it may be a Video balun issue???

maybe the camera has a defective light sensor for the IR ?

that switches the camera to the B&W mode when the IR lamps come on.

just a thought.

Hi,

What do you mean by dome infrared? Just to clarify. Are these day/night cameras that are going mono at the wrong time or colour cameras that are going mono.

I don't suppose you can connect an oscilloscope and do you know what a colour burst is? Perhaps the colour burst is being degraded for some reason. If the colour loss is regular can you unhook from the dvr and go straight into a monitor and check if it still goes mono.

I wouldn't have expected baluns to have problems over such sort distances but weirder things have happened.

Is it a long run for the cams that are going b/w