A motor control center supplies the following motor loads at

A motor control center supplies the following motor loads at an apartment complex: 20 hp, 460 V; 40 hp, 460 V; 60 hp, 460 V. The apartment\'s motor control center has been provisioned by a 480 V feeder. Determine the estimated load on the feeder.

Solution

The horsepower used for electrical machines is defined as exactly 746 W.^[21] In the US, nameplates on electrical motors show their power output in hp, not their power input. Outside the United States watts or kilowatts are generally used for electric motor ratings and in such usage it is the output power that is stated

so that

1HP=746 W

20*746=14920 W

40*746=29840 W

60*746=44760 W

14920+29840+44760=89520w

here the load on feeder = 89.520 KW