PoE Cabling

[sechs]

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]

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]

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.

 

[Stereodude]

The PoE voltage is fixed. The handsets might be low power, but the voltage doesn't change.

 

[sechs]

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.

 

[ddrueding]

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]

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.