**AMPERE:**A unit of intensity of electric current being produced in a conductor by the applied voltage.

**FREQUENCY:**The number of complete cycles per second of alternating current, e.g., 60 Hertz.

**HORSEPOWER:**The rate at which work is done. Ft is the result of the work done (stated in foot-pounds) divided by the time involved.

**INERTIA:**The property of physical matter to remain at rest unless acted on by some external force. Inertia usually concerns the driven load.

**MOTOR EFFICIENCY:**A measure of how effectively the motor turns electrical energy into mechanical energy. Motor efficiency is never 100% and is normally in the neighborhood of 85%.

**POWER FACTOR:**The ratio of the true power to the volt-amperes in an alternating current circuit or apparatus.

**SERVICE FACTOR:**A safety factor in some motors which allows the motor, when necessary, to deliver greater than rated horsepower.

**SYNCHRONOUS SPEED & SLIP:**the speed of an a-c motor at which the motor would operate if the rotor turned at the exact speed of the rotating magnetic field. However, in a-c induction motors, the rotor actually turns slightly slower. This difference is defined as slip and is expressed in percent of synchronous speed. Most induction motors have a slip of 1-3%.

**TORQUE:**that force which tends to produce torsion or rotation. In motors, it is considered to be the amount of force produced to turn the load, Tt is measured in lb.-ft.

**VOLTAGE:**a unit of electro-motive force. Ft is a force which, when applied to a conductor, will produce a current in the conductor.

Motor Terms Charts