Maximum POE output of a Cisco SG350 24 Port switch.

jreynolds4 · ‎02-16-2022

I am attempting to power 13 POE bluetooth receivers via a single sg350 POE switch. Each receiver consumes 7.5W (5V, 1.5A). The switch will power a maximum of 11 of the receivers. Does anyone know the maximum POE output of the switch? I have been looking for this specification, but so far I have only been able to find the max output per port. This is my first use of this model of switch and it is very possible that there is a step in the configuration that I have missed. Any thoughts on this would be greatly appreciated.

Martin Aleksandrov · ‎02-17-2022

Hi,

There are SF350-24P (supports 60W of PoE) and SG350-28P (supports 30W of PoE) models. Which one is yours?

Maximum power of 60W is delivered to any of the 60W PoE ports, and a maximum power of 30W is delivered to any of the other RJ45 network ports until the PoE budget for the switch is reached. The PoE budget for SF350-24P is 185W and for SG350-28P is 195W. Technical specifications are available at https://www.cisco.com/c/en/us/products/collateral/switches/small-business-smart-switches/data-sheet-c78-737359.html

jreynolds4 · ‎02-21-2022

The model of my switch, as printed on the front, is SG350X-24P. I was able to find the specs at Cisco 350X Series Stackable Managed Switches Data Sheet - Cisco
Model
Power dedicated to PoE
Number of ports that support PoE
SG350X-24PD
375W
24 (4 support 60W PoE)

As stated in the documentation "...and maximum power of 30W is delivered to any of the other RJ-45 network ports, until the PoE budget for the switch is reached.

The total power available for PoE per switch is as follows."

I am not using the 60W ports. I assume this does not affect the total POE budget. The devices being powered only consume 7.5W each. It seems to me that the switch should be able to support 50 devices at 7.5W. Some of the cable runs are around 200 feet and I assume the output increases to make up for cable loss. Still, I am only powering 13 devices at 7.5W each. There should be plenty of power. Is there a configuration I am missing?

Martin Aleksandrov · ‎02-22-2022

Hi jreynolds4,

If you indeed use an SG350X-24P switch, that basically means you do have 24 x PoE+ ports 4 of which are 60W capable. The total PoE budget for this switch is 195W (https://www.cisco.com/c/en/us/products/collateral/switches/350x-series-stackable-managed-switches/datasheet-c78-735986.html) and those 4 x 60W select ports count in this PoE budget. That being said, you can power on 24 x PoE (PD) devices if they require up to 7.5 Watts of power. Cable runs should be ok.

You can double-check if all devices require the same power and have the same type of PoE settings (using LLDP or manually applied value configured by the system administrator). Make sure all switch ports are set to either "port limit" or "class limit" type of PoE. It should be a Class Limit (the maximum power the device agrees to supply is determined by the results of the Classification stage). This means that it is set as per the Client's request using LLDP so you can check LLDP Statistics and/or LLDP Port Status when going to Administration-->LLDP Statistics/LLDP Port Status to see if end devices are recognized.