HORSEPOWER

SPEED       Use Exact

TYPE

FRAME

MANUFACTURER [ All ]GENERAL ELECTRIC

The AC slip ring or wound rotor motor is an induction machine where the stator is the same as is used with a standard squirrel cage motor, but the rotor is comprised of a set of coils that are terminated in slip rings to which external impedances can be connected. Brushes are used to make contact between a resistor bank and the rotor. By controlling the current, we can control the torque and speed of the motor by stepping in resistance. Slip ring motors are primarily used to start a high inertia load or loads that require very high starting torque across the full speed range. By correctly stepping in the resistors used in the secondary resistance or slip ring starter, the motor is able to produce maximum torque at a relatively low current from zero speed to full speed. A secondary use of the slip ring motor is to provide a means of speed control.