The plate on your electric motor might have a box that indicates the motor’s efficiency. Not all motors have this box, so if yours doesn’t, don’t be alarmed.

When electric motors are operated they generate heat. Some motors generate lots of heat (probably those that don’t show the motor efficiency on the plate) and some less so.

Heat generation by the motor indicates a of loss of energy, as the electricity is being used to generate heat rather than rotation. The more heat the motor generates, the less efficient it is in turning electricity into rotary motion.

Motors with higher efficiency ratings likely have more metal in their construction. Insulated metal is placed between the laminations to reduce eddy currents that produce energy wasting heat.

If you have an efficiency rating on the motor data plate of your motor, you will see a rating in percent, as in 86%, or you might see it as a decimal, as in .86.

When purchasing a motor, higher efficiency motors will reduce operating costs.