SG110-24HP PoE issues

[denis.briski1]

Hello,

We are having issues powering Axis P1428-E cameras using SG110-24HP switch (24 ports, of which 12 are PoE ports, total PoE budget 100W).

We tested and camera works OK in middle PoE ports (3, 4, 15, 16).

Other PoE ports power a camera a for a few seconds and after that the Status LED on camera reports that network connection is unavailable or lost.

At this time the network interface of camera is also available.

We have same cameras of the same type and all behave the same on all ports.

Data traffic works fine on all ports.

This cameras are PoE class 3 devices.

We heard unofficial information that on switches that have total PoE budget which is lower than the product of #of Ports and Class 3 PoE (in this example: 100W << 24*15 Watts), have some ports that can give less power and some ports that give more power. Is this information true? Or is such behaviour of PoE ports reason to create RMA?

Thank you!

Kind Regards,

Denis

[Philip D'Ath]

I would avoid using the low end unmanaged switches for applications like this.  You have no control over the PoE, no diagnostics and no monitoring.  It ends up costing a lot of time trying to resolve and fix issues.

I don't know about the unmanaged swicthes, but usually PoE is negotiated.  A device could ask for 7W, and another device could ask for 10W.  The power available to each port is based on what is negotiated per port.

The fact that the cameras are powering up briefly and then turn off suggested they have started the PoE negotiation, and the switch doesn't want to honour the request or can't honour it, and turns the power back off again.

[denis.briski1]

Thank you for your input.

I am aware that managed switch would be a much better solution. However, at the moment, this is a switch we have to work with.

I'm not sure why the same device would work on four of the ports (ports 3, 4, 15, 16) and not work on eight other ports.

Also, on this 8 ports, cameras work OK on some occasions, and then they lose connection. This usually happens once every 1-2 minutes.

Is it possible that some ports can provide more electrical current than other ports?

Or is this behaviour a sign of a defect?