how efficient are electric motors
This fact sheet briefly discusses several load estimation tech-. niques. Reasons to Determine Motor Loading. Most electric motors are designed to run at 50% to 100% of rated load. Maximum efficiency is. usually near 75% of rated load. Thus, a 10-horsepower (hp) motor has an acceptable load range of. 5 to 10 hp; peak efficiency is at 7.5 hp. A motor âs efficiency tends to decrease dramatically below. about 50% load. However, the range of good efficiency varies with individual motors and tends to. extend over a broader range for larger motors, as shown in Figure 1.