Powering camera by POE and 12v?

[badmop]

Is there a problem with powering a camera by the 12v pigtail and plugging it into a powered POE port at the same time? Or would it detect that it's already being powered by the 12v pigtail?

I'm asking because Where I will have 2 cameras I already have a 12v source and would like to power the cameras from that source (separate 12v power supply) Rather than POE. Call me weird, or just for knowledge sake, is there a problem to have it powered both ways?

 

[fenderman]

Is there a problem with powering a camera by the 12v pigtail and plugging it into a powered POE port at the same time? Or would it detect that it's already being powered by the 12v pigtail?

I'm asking because Where I will have 2 cameras I already have a 12v source and would like to power the cameras from that source (separate 12v power supply) Rather than POE. Call me weird, or just for knowledge sake, is there a problem to have it powered both ways?

The camera will only pull power from one of those sources most likely the 12v...but the real question is why on the world would you hook them up to both...makes no sense. Also remember that if you use the 12v, you need to have surge protection on that outlet.

 

[badmop]

Just curious that if somehow both were hooked up to make sure that it won't get fried, and just curious lol
If you already had it powered by 12v and you needed to connect the ethernet cable to get data, that cable would have to be plugged into the POE switch that's connected to the NVR, unless that switch had ports that weren't POE.

 

[bp2008]

If you have PoE then you might as well use it and not bother with the 12v. Unless the 12v is fed by batteries and the PoE is not fed by batteries and you are recording to an SD card.

 

[CamFan]

Not having access to the schematic, I would guess the poe power supply regulates to 12vdc. It likely meets the 12V pigtail input at this point. If designed right, they should be protected with diodes so one can't backfeed the other. Backfeeding the poe supply shouldn't be a problem. Most switching regulators can handle this. What you don't want is the poe 12v coming out the pigtail and feeding your battery or 12v supply. The extra load on the poe might not be good, and may blow it up if they didn't protect for it.

I would put a voltmeter on the pigtail with poe power, see if you get 12v. Let me know what you see.

If you see solid 12v, then there is no protection. You may need to add a diode.

Also measure your power supply output you planning feeding into the pigtail.

 

[badmop]

I was just curious, I imagine it is protected. I was just thinking what if someone hooked both up, instant fry or what.
Something to make sure you don't do if you're messing about, cause currently I was powering my dome by 12v and just regular cat6 plugged into the camera and into a network switch, until my dvr and poe switch arrive.