5.5. Application
The assembly of an asynchronous motor is much simpler, and
therefor also less costly and easier to service, than other motors. This applies
in particular to squirrel cage motors. Asynchronous motors are manufactured up
to 1000 KW performance. Survey 15 features the characteristic values for
asynchronous motors ranging from 0 12 to 4 KW. As speed control still poses some
difficulties, asynchronous motors are utilised in the first instance for drives
requiring a constant speed. These include, amongst others, compressors, pumps,
ventilators, many machine tools and textile machines. Asynchronous motors with
attached gears, so-called geared motors, are available for low-speed drives.
The slip ring motor finds application given complicated starting
conditions. Slip ring execution makes possible a certain degree of speed control
through the additional motor resistor or by means of an additional voltage in
the rotor circuit. A slip ring motor also permits counter current braking and,
consequently also employment as hoisting gear
drives.