Power Usage on a 7975 PoE Phone

[Fraser Reid]

Hi,

I would like to know exactly how many watts a 7975 uses on a cisco Swtich - it is a Class 3 device so a max of 15w is possible but I reckon that it will only use about 12.5 - the same as a 7965/45.

And then I would also like to know how much they use when the Screen has been turned off.

In other words I am thinking of buying this phone instead of 7965's when the power saving over night is large enough wih the display dimmed as I do not want to turn any phones completely off.....

thanks for any assistance .

Fraser

[fkarami]

Hi Fraser,

When Cisco Unified IP Phones are connected to common switches such as the Cisco Catalyst® 3560 Series Switches or Cisco Catalyst Series 3570 Switches, the switch can automatically detect the phone type and provide the exact amount of power that the phone needs. The use of Cisco Discovery Protocol provides this greater granularity to the power classification, allowing more accurate reporting of power consumption, and a higher density of phones on the same switch. The Cisco Unified IP Phone 7975G draws a maximum of 12W from a switch, placing it beyond the limits of Class 2 but below the default 15.4W value of Class.

You can get more info about the 79XX IP phones here:

http://www.cisco.com/en/US/products/hw/phones/ps379/index.html

Thanks,

Farbod

[Fraser Reid]

Thanks for your assistance Farbod but I was looking for a bit more indepth information. Rob got it just Right :-)

[fkarami]

No problems mate. Was not quite sure how in depth you needed the information to be.

Cheers,

Farbod

[Rob Huffman · Accepted solution]

Hi Fraser,

The numbers for the 7975 are included in this good doc

Cisco Unified IP Phones: Conserve Energy with Intelligent Power Allocation

http://www.cisco.com/en/US/prod/collateral/voicesw/ps6788/phones/ps379/white_paper_c11-481292.html

Cheers!

Rob

[Fraser Reid]

Thanks Rob - thats exactly what I was after - after about 2 hours of searching I gave up looking myself :-)

[Rob Huffman]

Hey Fraser,

You are most welcome my friend

With searches for this stuff;

"Sometimes you're the Windshield and sometimes you're the Bug"

Cheers!

Rob