208v to 120v power consumption

[LDoulias]

I am having a brain fart tonight...

If I have a Cisco 9300-24P using 200watts at 208v (as measured on a PDU), and I swapped it to a 120v power source, the wattage used would still be 200watts, correct?

Thank you

[Soichiro-Ono · Accepted solution]

Hello.

Answer is yes.

Voltage or current doesn't matter. First of all, the switch needs 200V for its operation to provide the power (watts) it needs. 

Then the only difference is whether the means to carry that 200 watts is 100V ( 2A ) or 208V ( 0.96A ).

Regard,

[Soichiro-Ono]

Supplement:

Since the point of view of the question was whether the power consumption of the switch changes with the input voltage, I answered " yes " in the sense that it does not depend and is not affected.

Also, the power consumption of the switch fluctuates with time (load status).

And note that the actual current input from the site's external power supply is higher than what is required by the switch, as current is lost in the line.

Regard,

[Joseph W. Doherty]

Should be about the same as wattage is volts times amperage.

Reason I note "about", in the real world, other variables come into play.