Using a powered ethernet connection as the input to a PoE injector?

Question

So I have a camera and a siren, both are driven by a PoE connection. I have a PoE switch, but it only can provide enough power to drive the siren. So what I want to do is hook both the camera and siren into the PoE switch, but run the connection to the camera through a PoE injector so it gets enough power. In this way I can run the camera and the siren with 1 PoE switch and 1 PoE injector rather than 2 PoE injectors and 1 unpowered switch.

Will I blow up my PoE injector if I use an already powered ethernet connection as the data input connection to the camera's PoE injector? This seems like a pretty unusual set up so I just figured I wanted to ask before I try it out and potentially fry my PoE injector.

Answer 1

You will need provide specific details, model numbers, 802.3af/at POE or passive POE, 10/100 Ethernet or gigabit Ethernet. If it is standard 802.3af/at POE you shouldn't have a problem. If it is passive, particularly GB passive your results might vary.