Abstract: An apparatus for starting and controlling a motor. The apparatus includes means for monitoring the load current values in each phase of a motor. These means can include an apparatus such as a current transformer. The apparatus utilizes a circuit for modeling a motor and estimating the temperatures of the motor's windings and housing. THe circuit preferably is defined by a programmed microprocessor. The estimated temperatures are based on the load current values and time. These estimated temperatures are then compared to allowable limits and, based on the comparison, the motor is either stopped or allowed to run.

Abstract: A rotor having cast squirrel cage windings is provided with a number of spacers for interrupting or spacing the stacked rotor laminations, thus forming vents for cooling. The spacers surround the rotor bars, and have a projection at each side thereof for fitting into the adjacent laminations. The design of the spacers allows them to be narrower than those previously known, thus enhancing air flow through the rotor.

Abstract: A dynamoelectric machine support frame wherein the stator mounting surfaces and the rotor bearing bracket mounting surfaces are all horizontally disposed in parallel planes. Further, in the preferred embodiment, all mounting surfaces on one lateral side of the frame are axially aligned with one another.