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PoE Injector Help - What are the differences?

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Hi Guys,

 

I have purchased a IP Camera from someone here in Thailand and firstly I am not 100% sure what brand the camera actually is. The sticker on the box says HD-C755R-POE but the little manual inside refers to "Hi3507". The guy selling it said it may have a different housing etc, so somewhat confused.

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Anyway my main question at the moment is how I can get POE to it. I am a little reluctant to buy a full blown POE switch just yet due to the cost and not knowing how far I will take this install just yet. I have a HP N54L Home Server being bought out to me and I plan to install Windows Server Essentials 2012 and use as a media server, downloader and now, hopefully a NVR using VMS on it (Blue Iris?).

 

At the moment I am a bit confused about the different products that inject power for POE devices. At first I saw bulky items like this, which seemed fairly expensive for each one (around £20+):

 

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Then I saw larger 8 port injectors that are the same kind of price but offer 8 POE:

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And now I recently found these cheaper splitter options:

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Am I correct in thinking the first more expensive option regulates the power the POE device needs, so you don't have to buy specific 12v injectors etc depending on the application? And that this conforms to the 802.3a/f standard? Meaning any a/f standard product could draw PoE from this regardless of its voltage and amp requirements?

 

If I went with the second 8 port option at the 12v my IP camera needs (12v 1a) would the camera be able to draw the correct AMP or would I need one of those splitters at the end as it does not seem to state AMPs the splitter gives, only voltage? If I went with this option I assume I would only be able to use specifically matched 12v devices with the injector?

 

Regarding the cheapest and final option. If I bought the correct 12v 1A plug and fed it into a splitter would I need to 'unsplit' the Ethernet at the camera end or can it carry the current into the Ethernet port?

 

Lastly can anyone advise if any of the 3 options would not work, or give a few pointers as to what you would do? I am in Thailand it can be tricky sourcing specific hardware and importing is very expensive here. As I am only playing with one camera at the moment I am on a bit of a budget, so steering towards the splitters at the moment then if it works well with my server in the future I could just chuck a PoE switch in the attic.

 

Cheers for your help

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If you are trying to power it via the ethernet cable you need a 48v 802.3af-compliant power source. Option 1.

Those other 12v passive inserters will likely fry your camera(they are not PoE/802.3af)

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If you are trying to power it via the ethernet cable you need a 48v 802.3af-compliant power source. Option 1.

Those other 12v passive inserters will likely fry your camera(they are not PoE/802.3af)

 

Option 2 is available in different voltages, one being 12v which I thought is what would be needed?

 

Does Option 1 dynamically adjust the voltage depending on the requirements of the device?

 

Option 3 I guess uses whatever power you put into it from the devices original adapter?

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option 1 is a standard 802.3af PoE midspan injector. 'True' PoE devices adhere to the 802.3af standard and run on 48v DC @ up to 15-watts. There is also 802.3at Hi-Power standard which can deliver 25-50w depending on the implementation.

 

Option 2 I don't know....is it advertised as 802.3af compliant? If not then its probably made for specific 'non-standard' type powered devices such as Ubiquiti NanoStation, Mikrotik, etc.

 

Option 3 just uses normal 'wall-wart' power supply and piggybacks it onto 2 unused pairs in the cable(only work with 10/100, no GigE). They might work for maybe like a 30' wire run but any longer I think you will have too much voltage drop

 

If your camera is 802.3af PoE, then your best/safest option is 802.3af compliant power source.

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also if your camera is in fact 802.3af compliant, the 12v rating you are seeing is for the secondary power connection if you power it via a separate power cable and not the ethernet connection.

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