Question about motor efficiency and its electrical "power" rating

[checkmatescott]

i have an oven fan motor and its rated at 15watts, is this output or consuption if its the output whats the efficiency, how many watts is needed to make it run at full capacity thanks i n advance

 

[Drakkith]

I believe that is the input power. I can't say that I've ever looked at an electrical device and seen a rating for output power that wasn't clearly labeled as such. It wouldn't make much sense to state the output power but not the input, as electrical safety would seem to require that the input be labeled to avoid overloading the circuit.

 

[checkmatescott]

thank you

 

[DaveE]

Yes, it's input power in normal operation.

 

[sophiecentaur]

Yes, it's input power in normal operation.

For pretty well every kind of machine, the input power is much easier to measure, for a start. Even steam engines have measurable cylinder dimensions and boiler pressure but it's anyones guess how well it will pull trucks up a hill or plough a field. 'Horse Power' used to be based more on a salesman's promise than anything else.