Hi everyone!
I'm studying up for my AE PE in April, and something's come up that's always bugged me in my cross-discipline practice: When discussing electrical motor loads with ME's and often in the context of energy modeling, I've often been referred to the "746W/HP" conversion to determine electrical requirements from mechanical equipment schedules. This straight conversion seems at odds with the procedure in electrical systems design that starts with the voltage/hp and determining the FLA using the NEC motor FLA tables at the end of Article 430.
I'm trying to understand where to draw the line between using the straight 746W/hp conversion and when to work from the NEC FLA's, as the AE PE exam apparently contains solutions that require the use of both approaches for different questions... a
Is it correct to say the FLA tables in NEC Art.430 are only to be used when sizing conductors/OCP/services and that in any other case concerning a motor's load given in horsepower, the 746W/HP straight conversion should be used?
I'm studying up for my AE PE in April, and something's come up that's always bugged me in my cross-discipline practice: When discussing electrical motor loads with ME's and often in the context of energy modeling, I've often been referred to the "746W/HP" conversion to determine electrical requirements from mechanical equipment schedules. This straight conversion seems at odds with the procedure in electrical systems design that starts with the voltage/hp and determining the FLA using the NEC motor FLA tables at the end of Article 430.
I'm trying to understand where to draw the line between using the straight 746W/hp conversion and when to work from the NEC FLA's, as the AE PE exam apparently contains solutions that require the use of both approaches for different questions... a
Is it correct to say the FLA tables in NEC Art.430 are only to be used when sizing conductors/OCP/services and that in any other case concerning a motor's load given in horsepower, the 746W/HP straight conversion should be used?