SG300-MP poe+ problem

[s.quartino]

Hi,

I have an issue with the poe delivered by sg300-28MP switches.

They are supposed to be poe+ capable switches

SG300-28MP-K9

●  26 10/100/1000 ports (24 PoE+ ports with 375W power budget)

●  2 combo mini-GBIC ports

When using a cisco sg300-28MP with a 1702i, the controler (2504 v8.0.110.0) says power injector/normal mode, and the power drawn is about 7-8 watts

When connecting the AP to a 2960X poe+, the controler says POE/full power, and the power drawn is about 16-17 watts.

I have one access point only connected on the switch, I'm using the last firmware. Do you have an idea why I'm not in full power with the sg300 ? I'd like to use the AP at their max rate

Do I need to open a case with cisco , am I alone with this issue ? Is cisco lying on the specs ?

BTW : I tested with multiple 1702i AP on multiple SG300-MP switches, always the same issue. I don't have any other poe+ client devices to test

Thank you

[Michal Bruncko]

Hi s.quartino

> says power injector/normal mode, and the power drawn is about 7-8 watts

can you confirm this with SG300 command:

switch#show power inline consumption

look for value of "Power[W]" column for related switch port.

I have SG300-28P (with PoE - "af" only) by hand with several WAP4410N AP's connected and Surveillance cameras. For all that AP's I can see power consumption between 5.700W - 6.300W. For surveillance cameras even smaller - 4W only. But all that equipments are working correctly without issues.

Are you observing any issues in our situation? I mean some issues resulted from smaller power provided by switch. Have that AP connected through SG300 switch providing same signal strength like same AP connected to C296X switch? Or you just focusing on power consumption only without having real impact?

> says power injector/normal mode

Doesn't this means that everything is in normal - from power providing strength by switch?

[s.quartino]

Hi Michal,

I'm not in front of the switch now but power consumption was 6w

The problem is :

when connected on standard poe this type of access point doesn't use all its antennas, so the coverage and/or bandwidth available will be lower.

The sg300 poe+ should be able to provide more than 15w per port. I suppose there is a bug somewhere or cisco is lying when saying the switch is poe+ enabled

For full power it should say : POE/full power instead of power injector/normal mode

[Michal Bruncko]

Then I would say open service request to Small Business Support Center (SBSC). I hope that this should be easily reproducible.

By the way - Power of 15W per port should be provided by regular PoE switch as well, no need to have PoE+. With PoE+ the input power per device can be increased to max 30 watts (more here, page 6). But looks like in this case even 15W is not provided by your PoE+ switch...

[alper.demircan1]

Hi s.quartino,

Did you fixed this problem? We've the same problem on our SG300s.

Regards

Alper