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Customer question on Power Wattage differences

Trusted Contributor

Customer question on Power Wattage differences

Philip was working with a customer and there was a question on enclosure power supply ratings:




All working with customer in training environment and looking for a way to explain the following question presented to instructor:


“It has been pointed out to me that the Power and Thermal screen show present power of 2491 Watts, while the Power Subsystem screen show that power supplies present Output is 2112 Watts.  Why are these numbers incorrect?”


Anyone have a good short description that can be provided to customer?



Some of the initial thoughts I shared – but customer looking for more:


Power Subsystem:

shows present enclosure power supplies, status and the Watts DC being output.


Power and Thermal: Enclosure Power Allocation:

Displays total power capacity in Watts DC

Power Allocated to potential max for enclosure in Watts DC

Power Available accounts for what’s left from capacity after allocation – in Watts DC


Enclosure Power and Thermal:

Enclosure Power (AC Input Power) would be the AC input draw that is being converted to DC

The AC input wattage draw is approx. calculation based on DC wattage from enclosure power supplies.

The AC input draw would be sufficient to provide for DC converted power that was needed by power supplies to provide Allocated Enclosure power.




Monty was able to help in this area:




Please refer to the OA v3.00 User Guide – page 174 “Enclosure Power Summary”


Present Power is AC Watts input to the enclosure.

Output Power from the power supplies is DC Watts internal to the enclosure.


The different in Present Power and Output power is the efficiency of the power supplies where:


Power supply efficiency = Output Power / Present Power.