Troubleshooting CAT5

[gian_18778 0]

Hi guys, gat a few questions here;

 

A friend of mine has a 8 camera CCTV setup around his property. He used CAT5 for his runs and dual power supply cameras. After everything is set up he's only receiving 4 video signals.

 

He and a friend of his pulled the wire to all locations and he performed a continuty test on all the lines, and everytihng check out fine. What's puzzling is that he is only receiving video for 4 cameras at the DVR.

 

He had one of his CCTV buddies to look at it but they could not solve it, and then he called me to see if I could assist. I'm no CCTV expert, but I know a little Electronics.

 

He is using a 12VDC 10AMP power supply for his distribution. He has passive video baluns at the cameras and 1-8CH passive video receiver at the head-end.

 

Here's what I found.

 

I read 11.98VDC at ALL camera locations, tested video and power lines for continuity, that was fine. I connected a monitor at the camera locally and did not get any video, however, I disconnected the camera and hooked it up directly to the power supply and got video. Did this for all cameras not seen at the DVR and ALL cameras produced video at the power supply. Wierd.

 

Tested the video baluns, and ALL transmit video. Out of the 4 cameras that can be seen at the DVR, three (3) of them are about 75ft. from the DVR and the furthest one has to be about 180-200ft away from the DVR.

 

It's strange. My friend did admit that *some* of the cable may have some stress or kinks in it during the installation of the wiring, but if you're still getting continuity, then that should signify that the cable is good, shouldn't it?

 

All in all, I did not know what to tell him. The cameras appear to be good, getting continuity on the pairs of the cable, I thought that the distance was going to be a problem, but one of the cameras currently being seen at the DVR is at least 180-200ft. away, I'm getting roughly 12VDC at each camera location, the only thing I could thing of was *maybe* there is some wire damage...

 

Any suggestions?

[rory 0]

Hi Gian, Im not an expert in the cat5 field, but what type of Cameras are they, also what are the Cameras Power Consumption and distances? Also is the power run using the cat5 cable, and if so is it a single pair or multiple?

[gian_18778 0]

Hey Rory, wassup man?

 

Ok, I just got the specs. These cameras do not have a name, like Pelco, or Sony or anything like that. It just states DSS (Digital Slow Shutter) High Resolution 3-Axis Digital Color Dome Camera (vandal proof).

 

Power Consumption: 330mA/4W (MAX)

 

*No distance for the camera power given.

 

Yes, the CAT5 provides power for ALL the cameras. Basically there is one CAT5 cable/ Camera. The Blue pair (Video), the Orange pair (Power).

[rory 0]

Ok was just checking as when using IR cameras doubt it would be able to power them beyond 50', at least that was the case when at one time someone I know tried IR Cameras on Cat5, even doubled up it had problems when the IR came on at night as it then went from 500ma to 1A. Best to use 18AWG cable, but since its not there right now, you could try to just double up the remaining pairs, should be 2 pairs left? Im actually surprised they are getting the distance with the other cameras you mentioned using 12VDC on that cable (180'?). 330ma is pretty low though, so may work if you just double it up.

 

Disconnect the baluns though and reconnect them also, just to be sure, if you haven't already done so.

 

 

Lastly, what is the brand of the Passive Receiver and Baluns?

Edited February 24, 2008 by Guest

[PMA 0]

Do you have any cat5 pairs available in those 4 cams?

Are the cams separated in 8 cat5 wires?

[PMA 0]

ok.... I see, 8 cat5 cables.

 

Easy to solve

1 pair for video (of the pair 1 wire for "tip or +" and another wire for "ring or -) blue pair

 

Then and just for those 4 cams, use a twisted pair for + (orange and oreange white) and another twisted pair for - (brown and brown white).

 

 

Don't forget to connect those new pairs in the power supply

[gian_18778 0]

Ok was just checking as when using IR cameras doubt it would be able to power them beyond 50', at least that was the case when at one time someone I know tried IR Cameras on Cat5, even doubled up it had problems when the IR came on at night as it then went from 500ma to 1A. Best to use 18AWG cable, but since its not there right now, you could try to just double up the remaining pairs, should be 2 pairs left? Im actually surprised they are getting the distance with the other cameras you mentioned using 12VDC on that cable (180'?). 330ma is pretty low though, so may work if you just double it up.

 

Disconnect the baluns though and reconnect them also, just to be sure, if you haven't already done so.

 

 

Lastly, what is the brand of the Passive Receiver and Baluns?

 

The CAT5 is 24AWG, forgot to mention that. The Baluns are NVT, no other name on it, the passive receiver, has no name on it So just double the power? or power and video?

[rory 0]

Well I would hope the Receiver is NVT also, otherwise surprised once again to see the 4 work at all!

 

NVT is a good brand.

 

Yes, for now just double it and see what happens. Try one camera first, in fact triple it if you can. Should be using 18AWG for power really. Thing is, if the cameras are powered up and not getting enough amps they will eventually die. If in doubt, buy some lamp cord cable and just run that for the power. Otherwise they sell RG59 Siamese CCTV Cable at Sure Alarms.

[gian_18778 0]

Well I would hope the Receiver is NVT also, otherwise surprised once again to see the 4 work at all!

 

NVT is a good brand.

 

Yes, for now just double it and see what happens. Try one camera first, in fact triple it if you can. Should be using 18AWG for power really. Thing is, if the cameras are powered up and not getting enough amps they will eventually die. If in doubt, buy some lamp cord cable and just run that for the power. Otherwise they sell RG59 Siamese CCTV Cable at Sure Alarms.

 

Hey thanks Rory, I'll try this and update my friend, I'll let you know what happens.

[Kiwi 0]

It looks to me like you measured the voltage at the camera with the camera disconnected? Otherwise I don't see how you could get close to 12V, there must be some voltage drop with the camera load. If you use the remaining 3 pairs for power, give each pair a plus and minus.

[gian_18778 0]

ok.... I see, 8 cat5 cables.

 

Easy to solve

1 pair for video (of the pair 1 wire for "tip or +" and another wire for "ring or -) blue pair

 

Then and just for those 4 cams, use a twisted pair for + (orange and oreange white) and another twisted pair for - (brown and brown white).

 

 

Don't forget to connect those new pairs in the power supply

 

 

Thanks

[gian_18778 0]

It looks to me like you measured the voltage at the camera with the camera disconnected? Otherwise I don't see how you could get close to 12V, there must be some voltage drop with the camera load. If you use the remaining 3 pairs for power, give each pair a plus and minus.

 

You're right I did measure the voltage w/ the camera disconnected. I did that to make certain that there was no significant voltage drop in the line. With the camera connected I got around 5.6VDC.

[gian_18778 0]

The problem is solved. Doubling the CAT5 on the power pairs did the job for 3 of the cameras, for the last camera (the furthest one out) looks like my friend may have to power the camera locally. If the power supply was a varible one, he might have been in luck. Overall he's happy, so I'm I, now I can get back to the NFL Network.

 

Thanks guys, if anyone else gives me a CCTV problem, I'll bounce it at you guys, and see if I can get it solved.

[PMA 0]

Ok my pleasure.

 

For that last camera that's not working you can try to add the last pair into the equation... and it might work.

 

Also add the green pair.

 

(+)

twist together the orange pair (orange and orange white) and add the green wire from the green pair.

 

(-)

Twist together the brown pair (brown and brown white) and add the green white wire from the green pair.

 

You may have a surprise, don't forget to connect them in the power supply.