poe switch in loft

[cbbella 0]

hi, i have a hikvision nvr with poe ports and 4x4mp hikvision poe cameras. i'd like to run the cat cables into my loft to a poe switch then one cable down to the nvr. the cables will be no longer than 25 metres. my question is does the poe switch need to be powered by an adapter or are there unpowered one's available as i don't have any plug sockets in my loft. i know i could run a power cable up to the switch but if there are unpowered one's available that would be better

[TheF 0]

I have not found any PoE switches that can be powered by PoE, but I know there are PoE splitters out there, converting that 48V to 12V usable by, let's say, a PoE switch.

https://www.aliexpress.com/wholesale?catId=0&initiative_id=SB_20180405005241&SearchText=poe+splitter

 

But the PoE splitters I have seen so far only split out 12V and not the 48V required by the PoE switch.

 

You might find a PoE splitter that yields 48V.

Just pay close attention to your power budget.

 

PoE switches comes in two different versions.

One is about 15W, the other is about 30W.

 

I have seen IP cameras using a range of 2w to 13w, depending on IR light, heater, PTZ function, motor zoom and so on.

 

Figure out how much your four cameras consume in total (should be listed in their spec sheet),

and make sure the switch and PoE unit downstairs can handle it all.

[tomcctv 190]

Hi. With no power in loft then just use a 4 way pass through Poe switch. They don’t cost much so just buy it local instead of going China

[cbbella 0]

Hi. With no power in loft then just use a 4 way pass through Poe switch. They don’t cost much so just buy it local instead of going China

 

thanks for the info, is this the sort of thing i would require as the power range of my nvr poe ports is 0-30.0w:

 

https://www.broadbandbuyer.com/products/30034-zyxel-gs1200-5hp-gb0101f/

 

regards