I haven't seen power requirements for an individual camera or security device in years. The power for all of the equipment is DC either routed on the coax or along separate wires in the camera cables. That DC is derived from the head-end equipment back at the Security Desk. Any 120V power that needs to be obtained locally (like pan/tilt/zoom) are wired in an armored flex.
I think the security world took a hard look at the cop shows in the 70's where the bad guys would just unplug the camera while they robbed the place.
