poe of voltage of different devices

Discussion in 'New Member Introductions' started by fredieng, Oct 10, 2018.

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  1. fredieng

    fredieng n3wb

    Sep 21, 2016
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    i have some questions about poe voltage output. i know for standard poe we talk about wattage and amp, for voltage i haven't find any discussion except standard 48v.
    in my place of work i have ubiquity with passive poe injector, cisco and one cheap nvr with 4 port with poe. i have measure the output voltage on each of them and they were different.
    once i tried to insert one ipcamera from the nvr set( no labeling on the camera) in to the ubiquity poe injector, and like one of the members here said, the magic smoke comes out of the camera, never heard about the camera after that.
    my question is if i plug those camera into the cisco switch , wich is old but have active poe supply normaly they will work??
    i have attached image of the measurement i have made and the only label that have my nvr kit.
    please comment your opinion

    Attached Files:

  2. alastairstevenson

    alastairstevenson Staff Member

    Oct 28, 2014
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    You simply need to look at the product specs for each device to see what standard they support.
    Most common is 802.3.af and for higher power 802.3at
    Any devices that support these will interoperate safely.

    Ubiquiti are not standards-conformant.
    Passive PoE is risky as there is no request/acknowledge dialogue that only initiates power to devices that support it.
    Damage may be caused to a device that it is connected to.
    looney2ns and tigerwillow1 like this.