Electric Motor Torque Ratings

An electric motor produces torque in response to load.

Electric motor torque ratings.

Electric motors have a rated horsepower hp. A motor does an amount of work equal to the torque it delivers times the angle through which it turns. 1 ft lb f 1 356 nm. If the torque requirements of the connected load increase beyond 1 horsepower and the motor is supplied either 208 volts 230 volts or 460 volts at 60 hz.

Electrical motor power velocity and torque equations. Motor power then is the torque times the angular speed. The actual speed of the turning rotor will slow down below the nameplate rated. An electric motor is an electrical machine that converts electrical energy into mechanical energy most electric motors operate through the interaction between the motor s magnetic field and electric current in a wire winding to generate force in the form of torque applied on the motor s shaft.

T ftlb p hp 5252 n 1b. The following calculators compute the various torque aspects of motors. T ftlb torque lb f ft. Reduced voltage soft starters.

Electric motors start up with very high torque level off slightly under and maintain that level throughout if they are overloaded the torque drops quickly and the motor stalls. You load it the rpm drops and it draws more current and produces more torque. T inlb p hp 63025 n 1. Accelerating torque available motor torque load torque.

It s easy to peg that as a hp rating measured torque at a fixed rpm. P t v 5 250. Horse power and speed in rpm. P hp horsepower delivered by the electric motor hp.

T inlb torque in lb f. Fla according to the voltage rating. N revolution per minute rpm alternatively. For an electric motor torque increases a gasoline motor has a peak torque value for a given rpm 3600.

Electric motors can be powered by direct current dc sources such as from batteries motor vehicles. These equations are for estimation only friction windage and other factors are not taken into consideration.