Hi.
I have connected 8 CCTV cameras over the BNC connector to DVR recorder. Everything works OK and picture is fine but there is one thing that i dont understand.
I have tested this problem with different 12V power supply's but the result is the same.
-------------------------------------------------- Installation cable: FTP shielded Maximum length from camera to recorder: 10 meters Wires used: blue pair for power, brown for video Wires for sensors ( the same FTP cable ): orange and green pair
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As you can see i have used 2 pairs for video and two for PIR sensors because camera is near sensor.
Problem: Ih i connect PLUS of ANY camera to ANY power supply ( 3 different ones ) the camera is working !
I dont need the negative / GND. The voltage between outer part of BNC and PLUS of power supply is 12V.
TESTS:
- we have tested all blue pair wires and none of them is in short circuit, nor there is any voltage on the wires. The recorder is on the metal carrier that is connected on the metal profile but DVR is on rubber stands so this can not be a problem.
I have tested one PSU with eight 12V outputs, one 12V / 5A switch, one
12V/1A switch. Every time the same situation.----------------------------- I would understand if one pair makes this kind of problem but all of them, this is simply not possible.
Where could be a problem ?