Star Delta Starters

How Star-Delta starters work for 3 phase induction motors.

 

Normally it can be easily confirmed by motor manufacturer how and if, a motor can be connected to a Star Delta starter.

 

Mainly because of In-rush current.

Current can be reduced 1/3 in Star-circuit due to the reduced voltage and current.

Motor Terminal Box connection

If U1-W2, V1-U2, W1-V2 can be shorted, it is Delta configuration. Using Delta Contactor.

If U2-V2-W2 are shorted, it is Star configuration. Using Star Contactor

 

 

Delta Configuration

Star Configuration

 

To automate this, we need three contactors operated by switch or timer.

#Main contactor

#Delta contactor

#Star contactor

Control the changeover as mentioned, simply use a timer.

After a set amount of time, it will automatically change the configuration.

Once amps or motor speed has been monitored, it can allow advanced application.

 

 

<Supplement>

RED YELLOW BLUE

BROWN BLACK BLUE

 

why?

 

 

Studied from

The Engineering Mindset

(theengineeringmindset.com)