TheoR
Posts: 1
Joined: Fri Oct 12, 2018 10:41 am

Is the PoE HAT really class 2?

Fri Oct 19, 2018 12:30 pm

The Raspberry Pi PoE HAT specifications indicate that it is a PoE class 2 device. Nevertheless my switch indicates it is a class 3 device.
According to Wikipedia (https://en.wikipedia.org/wiki/Power_over_Ethernet) class 2 has a power range of 3.84-6.49 W, where class 3 has 6.49-12.95 W available on the PD. Also the PoE HAT specification indicates 5V/2.5 A DC output, which is far beyond class 2 range..
Is the official specifcation wrong or am I misinterpreting?

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Burngate
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Location: Berkshire UK Tralfamadore
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Re: Is the PoE HAT really class 2?

Fri Oct 19, 2018 6:20 pm

I'm no expert, and I can't find any reference to such low power ranges on the Wikipedia page.

The only reference there, in the first table, gives 25.5W and 51W.

stevend
Posts: 209
Joined: Fri Oct 11, 2013 12:28 pm

Re: Is the PoE HAT really class 2?

Fri Oct 19, 2018 7:38 pm

Burngate wrote:
Fri Oct 19, 2018 6:20 pm
I'm no expert, and I can't find any reference to such low power ranges on the Wikipedia page.
Second table

It does look as if a Pi is more likely to be Class 3 than Class 2 - in fact, right at the limits of a Type 1 device. It will depend a bit on the peripherals powered.

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