FM100 Maintenance & Operations Manual - TECO-Westinghouse ...

Constant Torque Loads. When the motors output current exceeds 103% of the motors protectiveelectronic thermal characteristics during the start operation, the Inverters protective (OL1) willallow operation of the drive for 150% of rated current for 60 seconds before shutting the Invertersoutput off.Percenl Torque and Horsepower10050TorqueHorsepower0 50Percenl Speed100Constant Torque Loads:With a Constant Torque Load, thetorque loading is not a function ofspeed. This is a characteristic oftraction drives, conveyors, positivedisplacement pumps, etc.As the speed changes, the loadtorque will remain constant and thehorsepower will change linearly withthe speed.Variable Torque Loads (Fans, Pumps...etc.) When the motors output current exceeds 113% of themotor’s protective electronic thermal characteristics during the start operation, the Invertersprotective (OL1) will allow the drive to operate at 123% for 60 seconds before shutting theInverters output off.+Percenl Torquc and Horsepower1002512.50TorqueHorsepower50 100Percent SpeedVariable Torque Loads:With a Variable Torque Load, torqueloading is a function of speed. Thisis characteristic of centrifugalpumps, and certain types of fansand blowers. As the speed isincreased, typically the torque willincrease with the square of thespeed and the horsepower willincrease with the cube of the speed.42