Cisco Power Specification

matthewbevan · ‎07-17-2009

Hi All,

I am looking to audit the power consumption of my cisco devices. I wanted to know what power my 3750 was consuming so I checked the following data sheet information:

Power Requirements

AC input voltage 100 to 240 VAC (autoranging)

0.6 to 1.2 A, 50 to 60 Hz

DC input voltages for

RPS 2300 and 675

+12 V @13 A

Power consumption 120 W, 409 BTUs per hour

Power rating 0.120 kVA

However, I cannot see where the 120W power consumption comes from as with the supllied AC input voltages I get 288W and when I do the rms calculation to obtain a power rating I get 140kVA!? I'm in a rut here can someone point me in the right direction or at least prove I'm not going mad with my calculations!

Thanks,

Matt.

Giuseppe Larosa · ‎07-17-2009

Hello Matt,

I'm not sure because I use watts but I think

1 kVA = 1000 W

so 0.120 kVA should mean 120 W

see

http://www.powerstream.com/VA-Watts.htm

>>

What is KVA?

KVA is just kilovolt-amps, or volts times amps divided by 1000:

KVAÂ·PF = KW (any load, including inductive load

there is also the power factor that for me for AC is 0.707 but I see that for a generic load (impedence ) is between 0.35 and 0.90.

Hope to help

Giuseppe