[email protected] wrote:
I have such a cable + PSU combo on my workbench which I use to power up ALIX boards that I use. Now a different colour from the others!
One of the reasons that I insist that all PoE cables and PoE capable switches are coloured/labelled separately from everything else where I work. I use red cables throughout the school I work just for PoE. Nobody touches the red cables, and there's no "extending" them or "replacing" them or "moving" them or anything else. Outside the other end of a suitable PoE-sucking device, on it's unpowered daisychained port, sure we just chop and change and crimp Ethernet like normal.
Although you're talking about a "homebrew" style of PoE, and the standardised versions are much safer, the only thing stopping that voltage running down the cable is the sensing of a certain resistance between two of the pins, and then when it's "live" you can have dozens of watts pumping down some cable.
Otherwise, it's only a matter of time before some smart-alec workman thinks "I'll just cut that and extend it" and gets 25W up his tool or, worse, manages to push it into other unpowered data wiring within the same cut and take things out.