Motors

[JasonMT]

Im working on a 2008 Nec JW practice exam. The question is "What is the feeder conductor ampacity required for two-2hp, single-phase, 115v motors. I multiply 24amps by 2motors by 125% =60amps. There answer is 54amps. What am I doing wrong.

Thank you.

 

[david luchini]

Im working on a 2008 Nec JW practice exam. The question is "What is the feeder conductor ampacity required for two-2hp, single-phase, 115v motors. I multiply 24amps by 2motors by 125% =60amps. There answer is 54amps. What am I doing wrong.

Thank you.

You only have to add 25% for one of the motors, not both. (This would be the largest motor, but in your case they are the same size.)

24*1.25 + 24 = 54