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2/2/2017 10:31:33 AM
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Re: 220VAC
Sorry Chad---that 220 VAC reference should not have been in there. Thanks for the catch!

Chad Jones
Chad Jones
2/1/2017 5:42:20 PM
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"220VAC power has to be applied with twisted pair via 0.125W resistors. The current via these resistors is small and has no danger of overheating." Where does this statement come from? I hope this sentence was a typo that was orphaned during a review. I would never consider putting 220VAC onto standard Ethernet cable and call that safe. Please do the readers a service and remove this sentence from the article. 

As you pointed out, the typical PoE voltage range is 44-57V. This was carefully chosen to comply to Safety Extra Low Voltage (SELV) standards and is considered safe for human contact. Add to that the detection mechanism of PoE where an unconnected cable won't have an applied voltage, the entire system has been over engineered to ensure safety. It's a scary thought that someone could read this article and think it is OK to apply 220VAC 'via 0.125W resistors'.


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