Slip Ring Motor-stator Connection

[boby]

a 415 volts 50 hz slip ring motor stator connected in star and some of them connected in delta,why is there so much of variation,suppose if we use a star connected stator the voltage applied to the stator reduces,torque also reduces then why some stators of a slip ring motor connected in star a 415 volts 50 hz supply.what happens if rotor connected in delta?

[marke]

Hello boby

 

You must connect the motor in the configuration (star or delta) for which it was designed at the voltage you are running.

 

There are a number of posts about this on this forum, but essentially, the motor is designed to operate with a fixed flux in the stator. In order to develop this flux, the windings are designed for a particular voltage. Changing the connection from star to delta at a fixed voltage, changes the voltage accross the windings and will change the flux.

 

If the motor was designed to be connected in star at you voltage, you must connect it in star.

If the motor was designed to be connected in delta at your voltage, then you should connect it in delta. If you connect a delta designed motor in star, you are reducing the voltage across the stator windings to 57% (1/rt 3) and you are reducing the flux. this results in the effective rating of the motor being one third of it's normal rating.

 

A motor designed to operate in star will perform the same as a motor designed to operate in delta. You will not see any difference in operation provided that it is connected as designed. (name plate data)

 

Best regards,