3 Phase Motor Feeder

[69spark]

This question was on a stateboard web site, i was curious to see what answer some bodyelse got

A feeder supplies three 460-volt, three-phase, 1740 RPM, Design B, alternating-current motors. The motors have the following nameplate ratings: 25 horsepower, 28.4 amperes; 15 horsepower, 18.2 amperes; and 10 horsepower, 11.3 amperes. Assuming all the motors are operating under continuous duty, what minimum size XHHW-2 feeder circuit conductors are required to supply the motor load? The conductor terminations are rated at 75?C


Here's what I got:

460 volt 3 ph
25hp=34amps x 1.25=42.5 77.5 amps=2awg xhhw-2
15hp=21amps + 21
10hp=14amps + 14

 

[RUWired]

This question was on a stateboard web site, i was curious to see what answer some bodyelse got

A feeder supplies three 460-volt, three-phase, 1740 RPM, Design B, alternating-current motors. The motors have the following nameplate ratings: 25 horsepower, 28.4 amperes; 15 horsepower, 18.2 amperes; and 10 horsepower, 11.3 amperes. Assuming all the motors are operating under continuous duty, what minimum size XHHW-2 feeder circuit conductors are required to supply the motor load? The conductor terminations are rated at 75?C


Here's what I got:

460 volt 3 ph
25hp=34amps x 1.25=42.5 77.5 amps=2awg xhhw-2
15hp=21amps + 21
10hp=14amps + 14

#4 cu. or #2 al would be correct.