I have a PowerEdge T410 which comes with redundant power supply. My understanding was that with both connected, combined, the machine would draw only as much power as it needs, and would be the same if just one is connected.

But checking the sensor reading with ipmitools, it seems like the power usage (watts used) is almost double with both connected.

Readings with one PSU connected:

Current          | 0.68 Amps         | ok
Voltage          | 118 Volts         | ok
System Level     | 98 Watts          | ok
Power Optimized  | 0x00              | ok
DKM Status       | 0x00              | ok

With both PSUs connected:

Current          | 0.80 Amps         | ok
Current          | 0.80 Amps         | ok
Voltage          | 118 Volts         | ok
Voltage          | 118 Volts         | ok
System Level     | 189 Watts         | ok
Power Optimized  | 0x00              | ok
DKM Status       | 0x00              | ok

 Is my understanding correct that its using double the power, or am I reading the sensor output wrong?