Exercises

 


 

Part Winding start-up

This chapter will study the motor start-up procedure known as "part winding", which is commonly used is refrigeration and air-conditioning to avoid some of the problems that we have already looked at...

EXERCISE : On testing this compressor motor, you find a resistance of about 0.2 W between the terminals U1 and V1, U1 and W1, and between V1 and W1. You say to yourself that this must be a PW motor.

You then test the right hand row and find about 0.4 W between terminals U2 and V2, U2 and W2, V2 and W2, that is, a resistance about twice the earlier value. In addition, there is no connection between the three left-hand terminals and the right hand connections.

So what type of motor is this?

(Solution : Refrepair Manual pages 449 to 463)

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