Is the output of electric motors still given in horsepower?� I have been on some small appliance web sites and they give the power of the motors in amps.� When i was growing up in the fifty's i seem to remember that horsepower was rated differently on�gas and diesel engines between the U K and North America.� I don't know if Kilowatts would ever be excepted in North America, because everybody uses horsepower�all the time.� Is the torque output for electric motors measured in ft lbs?� Is the power output between a five horsepower electric motor and a five horsepower gas or diesel engine the same? Thanks a lot everybody for all your help.������
I am unable to reply to all the points that John has raised; however the AC motor is more complex that it might appear. It produces an electromotive force that opposes the external power supply. The result is that the voltage at the input leads the current wave, and the power input is not the simple product of volts times amps, but volt-amps. The input volts may be aligned with the input amps by putting a capacitor in an input lead, with the result that the amps at the input are delayed to come into phase with the volts. The result is that the input is watts = volt-amps. This refinement is omitted is the case of small motors. I think that it is to avoid such explanations that mechanical output is expressed in horsepower.
By the way, the French *cheval-vapeur* is 75 m�tre-kilograms = 735.498 75 W, while the British horsepower is 550 ft,lbf/s = 745.699 9.. W
Joseph B. Reid
17 Glebe Road West
Toronto M5P 1C8 Email: [EMAIL PROTECTED]
