Quick 203 question - Resistors on motor windings

[1eye101]

Whislt studying for my 203 exam tomorrow I came accross the following question that I can't find the answer to! Any help greatly appreciated...

Why are resistors installed in motor windings? How are they connected?

All I can think of is for single phase ac motor on the run winding to cause the voltage and current to be out of phase with the start winding. Am I on the right track? I'm not finding any answers in my text book or google.

Thanks in advance

 

[oldtimespark]

It is more usual to have thermistors fitted in the motor windings see link

they are used to monitor the motor temperature via a control unit.

 

[msb2003]

to late for the exam I'm afraid, hope you passed. Induction motors can be squirrel cage or wound rotor, where the windings are tapped off, via slip rings and brushes to external resistors to allow control of the inducted current and therefore control the rotors magnetic field.

regards

Mark