Problems with Surveillance Cameras

Without more info... any response is a guess. But it sounds like "voltage drop" is your problem, more then likely caused by power cables that are to small. The level of the voltage getting to your field devices is below the level required for the cameras to work.

Options...

New larger cables or... split the power delivery system in to two or more sections and place additional power supplies on each of the new sections.

I'm with you on that!

Guest, When you plug the camera into a local supply you say the camera is OK. Have you measured the power supply that should be suppling the camera at the camera? Does this have a voltage? Has the circuit been checked to see if it does go back to the supply or is there a break in the line? Has this system ever worked in the past? When using 12V/24V, you want the transformer near to the device due to reasons stated by North of 60!

All the best..

If you already have a line ran for all the camera's to feed off one supply, find some 3-tab 12 regulators (like a LM7812) to put at each camera. My experience with them is that they must have a certain level very close to 12 VDC or there will be problems.

Multiply the current (amps or milliamps) by the number of camera's and add about 20% to allow for the regulators internal requirements.

Some need a higher input than others so starting with about 24VDC (unregulated will do)

They only need 2 small bypass caps according to this link: http://www.fairchildsemi.com/ds/LM/LM7812.pdf

The schematics are at the bottom and it (the PDF) is fairly long. Should cover anything you need to know, however.