It is a fundamental principle of a winding that adjacent poles
must be wound to give opposite magnetic polarity. This does not mean that the coils actually
have to be wound in this direction before being placed into the stator. It does mean that the winding must be connected
so that, if the current proceeds through one pole in a clockwise direction,
it must proceed through the next pole in a counterclockwise direction.
This principle is used to determine the correctness of connection diagrams.
Motors in NEMA 143T to 449T frames.
A measure of an insulation system’s resistance. This is usually measured in megohms and tested
by passing a high voltage at low current through the motor windings and measuring
the resistance of the various insulation systems.
A device that takes electrical energy and converts it into
mechanical energy to turn a shaft.
A motor wound in such a way that varying connections at the
starter can change the speed to a predetermined speed. The most common multispeed motor is a two-speed
although three- and four-speeds are sometimes available. Multispeed motors can be wound with two sets
of windings or one winding. They are
also available with constant torque, variable torque or constant horsepower.