Electric Motor Torque Ratings

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.

Electric motor torque ratings.

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. It s easy to peg that as a hp rating measured torque at a fixed rpm. You load it the rpm drops and it draws more current and produces more torque. The following calculators compute the various torque aspects of motors.

Torque in imperial units can be calculated as. An electric motor produces torque in response to load. Gas engines are usually rated for horsepower and torque at a specific rpm go under or especially over and the torque drops off. Fla according to the voltage rating.

T inlb torque in lb f. 1 ft lb f 1 356 nm. A motor does an amount of work equal to the torque it delivers times the angle through which it turns. Horse power and speed in rpm.

N revolution per minute rpm alternatively. Reduced voltage soft starters are used to limit the start current reducing the locked rotor torque or starting torque and are common in applications which is hard to start or must be handled with care like positive displacement pumps cranes elevators and similar. P t v 5 250. P hp horsepower delivered by the electric motor hp.

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. Accelerating torque available motor torque load torque. Electrical motor power velocity and torque equations.

T inlb p hp 63025 n 1. These equations are for estimation only friction windage and other factors are not taken into consideration. T ftlb torque lb f ft. T ftlb p hp 5252 n 1b.

Motor power then is the torque times the angular speed. The actual speed of the turning rotor will slow down below the nameplate rated.