Myths about Power Over Ethernet

Wojciech Puchar wojtek at
Sun May 31 08:38:51 UTC 2009

> Myths about Power Over Ethernet
> May 28, 2009
> Power-over-Ethernet (PoE) technology integrates power and data across standard Cat5/5e/6 network cabling and provides more flexibility in today?s workplace. PoE enables power to be supplied to network devices, such as IP phones, network cameras, and wireless access points through a single, most often existing, network cable. When combined with an uninterruptable power supply (UPS) a PoE network delivers continuous operation and minimizes business downtime by eliminating most power interruptions. With the ability to install endpoints in any location PoE technology provides a scalable and flexible networking infrastructure geared for growth and efficiency.

Unless gigabit ethernet is used, the simplest PoE is to put + on brown 
pair and - on blue pair, as only green and orange pairs are used. 
Unless the device doesn't have low voltage like 5V or less as input and 
doesn't suck too much power it's just fine, and requires just 5-10 minutes 
or work, soldering iron and insulation tape.

It's really funny to see "PoE converter" sets costing at least 150PLN 
(45$) here doing exactly the same. of course nobody forbids anyone to 
spent too much :)

I even know somebody that had a lots of equipment with american-style 
power (110V AC), made 220 to 110V transformer and actually put 110V AC 

It worked but really - it wasn't safe IMHO :)

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