I am trying to confirm power requirements for a switch. I have a Cisco C9300L-24T-4G switch. I am running 120VAC power for my power system to the switch/network cabinet. The standard power supply for this switch is 350 watts. The Cisco catalyst 9300 Series Switches datasheet document shows table 22 Power Consumption of Standalone 9300 Series Switches (tested on IOS XE 16.5.1) (page 53 of 76) states that at 100% full port traffic the switch will only consume 72.37 watts.
To be safe I am assuming the switch is running at 100% capacity at all times (this is not the case) and therefore the full load amps of the switch only be 72.37 watts / 120 VAC = 0.603 Amps and not the 350 watts / 120 VAC = 2.92 Amps if you based the amps on the power supply for the switch as the power supply will only supply the among of current/power/watts demanded by the switch that it feeds.
Obviously I have several of these switches in one cabinet and there will be some small power losses in the power supplies that feed the switches, but for simplicity I will use 0.603 Amps +5% additional capacity (for power losses in the power supply) for each switch I have in a cabinet. Therefore if I have 30 of these switches in a cabinet I will need to account for roughly a 19 Amp power feed @ 120V to the cabinet to properly (assuming there are no other loads in the cabinet) run the cabinet and all of the switches in the cabinet. Can some verify this line of thinking is correct or if not what is the industry standard for coming up with power requirements for switches? Do you use the datasheet numbers for specific switches or do you use the power supply requirements even though that is overkill?
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