PoE Cabling

sechs

Storage? I am Storage!
Joined
Feb 1, 2003
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#1
How much does the cabling matter with power over ethernet?

My story: I've ordered and LTE modem that needs to be stuck in a window for reception purposes. It would be much easier to use PoE than running an extension cord back to the UPS. I estimate the maximum wire distance from the injector to the modem to be three meters -- it'll probably be closer to two.

All of the stuff that I'm reading online says that you gotta use cat 6a cables. But they all seem to be referencing long-run, infrastructure wiring.

Can I use one of my existing cat 5e cables for this short run or am I really better off picking up cat 6/6a?
 

Stereodude

Not really a
Joined
Jan 22, 2002
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Michigan
#2
I don't see why it wouldn't work with your existing CAT5e cables given how short the run is.

I've seen lots of VOIP setups using CAT5e and PoE.
 

sechs

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#3
VOIP handsets are generally low voltage/low power.

I'm not exactly sure how much this modem will be using, but it's 802.3at, up to 30W.
 

sechs

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#5
Found this calculator, and it looks like, as long as it doesn't catch on fire, any Cat5e or higher cable will do.

It also turns out that I only have one cable of appropriate length that's not in use, so I have to order one anyway. :rolleyes:
 
Joined
Feb 4, 2002
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Monterey, CA
#6
You'll be fine. I've run 35W+ wireless links on the end of 150' Cat5e STP cables without issue. I've never even had a cable get warm (could be because the STP I use has braided steel around it?
 

sechs

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#7
This would have been a UTP cable, but I doubt it would have been a big difference.

Went ahead and picked-up a five-pack of Cat 6 STP cables.
 
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