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In which occasion does Cat 6509 can draw 6,000Watts?

Hi, my Cisco representative tells me that the Cat 6509 I am buying typically draws 1,800 Watts. However he reckons that the specs tell me it can draw up to 6,000 Watts - what is a lot!

Can someone explain how can this be? Since the Cat 6509 has (2) redundant power supplies built-in, I should plan to use for power cables, right? Someone told me that in the past, one Cat 6509 required up to (4) power cables and I am not sure if I understand that is true.


Re: In which occasion does Cat 6509 can draw 6,000Watts?

it would depend on the Sup and rhe modules you will use to populate the chassis.

The Power drawn is particularly high when you need to enable PoE modules

Refer to the power calculator url below (requires CCO) for calculating the power requirements



Community Member

Re: In which occasion does Cat 6509 can draw 6,000Watts?

It would depend upon the modules you have installed. And if they were all PoE blades, how many devices they were powering.

I have a mixed environment in my 6509, inasmuch as the blades are all PoE, but not all the ports are providing power to the connected device (211 on out of 336, most class 2 devices).

Currently, I am using just over 3000 watts (including PoE) in one of my 6509's. If I changed the SUPs from 32's to 720's, that would change my draw slightly, or if I moved to other modules, they might draw more as well. For example, the WS-X6748-GE-TX draws 407.40 watts, and the WS-X6148A-GE-45AF draws 112.56 watts (excluding PoE draw). So if I filled my chassis with 7 WS-X6748-GE-TXs and 2 SUP720s, I'd be closer to 4000 watts. If I filled it with 8 port 10 GigE blades, I'd be pushing 5000 watts.

When there are 2 power supplies in the chassis, they are there in the event of a failure. When one supply fails, the other would would need to handle the complete load.

Also, there are two slots for supplies in the 6509. Unless there's a bundle that you are looking at purchasing, then power supplies are optional when ordering the chassis. You must order an appropriate sized power supply (or two) seperately.

The WS-CAC-6000W power supplies have 2 220 volt single phase power cords each. This is because of cable and connector ratings. A single connector is rated to (I believe 20 Amps or 20 X 220 = 4400 Watts). Unless you wanted to use very expensive and need to be wired in accordance with local electrical codes by an electrician - connectors, the use of two cables saves you money and time and....

I hope this has been helpful. FWIW, I am not a Cisco employee and I'm not trying to push the same info. It's simply mathmatics and physics. Your sales person is giving you correct information.

Community Member

Re: In which occasion does Cat 6509 can draw 6,000Watts?

Great explanation. Thanks.

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