How do I calculate the toruqe required and the HP required for a DC motor to be replaced with AC motor and Drive. the Dc motor is of 90hp, 1500 rpm drives an extruder.
ysn,
Three things determine the torque produced by an AC induction motor;
1= the strength of the magnetic field of the stator
2= the strength of the magnetic field of the rotor
3= the phase angle difference between rotor and stator fields.
There are several formulas for configuring the info you request, try your local electrical parts dealer for a copy of Uglys engineers pocket reference guides,inside you will find several formulas for conversion needs,also Delmars Textbooks are an excellent source for this info, hope this helps.
JB
Is the extruder started loaded or unloaded? What was the starting torque of the DC motor? 90X5250/1500=315ft/pds of torque running. Suppose you are using 50Hz., since the 1500RPM. Some DC motors have high starting torque, higher than their AC equivalents. Most Design B motors, according the MG-1 NEMA have a 150% locked rotor torque or better.