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Hikvision cameras with Cisco AIR-PWRINJ4 Power injectors.

Eugene G

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Has anyone had experience powering Hikvision cameras with Cisco power injectors?
I have checked the specification of both and they both support the IEEE 802.3af standard. Confusion kicks in with the voltage rating; the power injector is rated at 48V and the camera does not specify a voltage other than it’s DC supply of 12V. 802.3af is rated at 24-48V so logic would dictate that there would be a negotiation between the camera and the injector to choose the appropriate voltage.
 

Phil

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All will be fine.
You have done the correct thing in checking that your POE injector is compliant with the IEEE 802.3af standard.
It is essentially just a nominal carrier voltage.
It needs to be that high to enable power to successfully travel up to 100m and be able to POE power the camera.
Once the power arrives at the camera's network connection the camera's internal electronics will step the voltage down as required.

There is also an initial handshake between a POE supplying device and the powered device, which checks that the device is one that can accept POE power e.g. so that you could say connect a PC (that does not require POE) to a POE switch port (that is able to supply POE, but needs to check before doing so whether the device needs it).
 

SteveR

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#3
Has anyone had experience powering Hikvision cameras with Cisco power injectors?
I have checked the specification of both and they both support the IEEE 802.3af standard. Confusion kicks in with the voltage rating; the power injector is rated at 48V and the camera does not specify a voltage other than it’s DC supply of 12V. 802.3af is rated at 24-48V so logic would dictate that there would be a negotiation between the camera and the injector to choose the appropriate voltage.
Hi Eugene, You have probably sorted it by now but if not, then just to re assure you I have used both and AIR-PWRINJ4= and AIR-PWRINJ6= power injectors on POE Hikvision cameras they will run up to 30 Watts under 802.3at (and 15.4 watts under 802.3af) so plenty of power available at the port. (the AIR-PWRINJ6= being the replacement for the now end of life AIR-PWRINJ4=). As Phil mentions above the camera has a DC to DC converter that drops the voltage to 12DC internally and the handshaking sorts out the power requirements of the device. Sometimes this is built into the external RJ45 dongle connection of the camera, so it is very important that those connections are good and waterproof.
Cheers Steve
 
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