CISCO 3945 Router - ARE POWER SUPPLIES LOAD BALANCED?

[olga.aceves]

CISCO 3945 Routers - Are the 3945 Router power supplies load balanced by default?  

We are trying to determine if our switch/server rack at our remote location has maxed out it's power load requirements.  I just need to know if the 3945 power supplies load balance by default or if the redundant power supply is ON but not really providing the router with power and is just there incase the other power supply fails - Thank you.

[turnera]

The 3845 power supplies load share so I am reasonably sure the 3945's do as well.

The following link to the data sheet shows this to be true.

http://www.cisco.com/en/US/customer/prod/collateral/routers/ps10536/data_sheet_c78_553924.html

[olga.aceves]

Thank you for your reply. I had read that the "Cisco 3845 and 3845-NOVPN router accommodates two hot-swappable power supplies and a single power supply meets router requirements. The second power supply provides redundancy, load sharing, and increased router availability. Either power supply can be removed without affecting router operation. Any combination of two power supplies is permitted."

Unfortunately, I couldn't find any specific information for the 3900 series routers that stated it also load balanced power.

Follow-up question: Do you know if the 3800 series routers load share by default? I know it is capable of power load sharing based on the above description but do they load share equally by default? If that's the case for the 3800's then hopefully that's the case for the 3900'S series routers. Which means, we have not maxed out our power requirements in our racks.

[Leo Laohoo]

Dual PS of the routers don't go like "I'll do half a load and you'll do half a load".  Doesn't work like that.

Both PS push full power and the router self-regulate how much it takes (like going to a buffet).