How to Wire a Star Delta Motor

Updated February 21, 2017

The difference between Star and Delta is the generated voltage taken from an electrical current. The Star motor is high voltage that uses a low current. The Delta motor is a low voltage motor that uses a high current. You can calculate the AC voltage required in Star or Delta by taking the voltage from one coil and multiplying it by the number of coils per phase. This figure is the phase voltage measurement. The Star and Delta motors give off the same power, but the generation of that power is different.

Strip the ends of all 6 windings from the 3 sets of coils. The wires need stripping so they can connect properly to the screw terminals.

Read the labels on the 6 windings. You will have A1, A2, A3, B1, B2 and B3. The numbers represent the separate phase windings and the letters represent the beginning and end of each winding.

Match the windings for the Star motor in this manner: B1 to B2 and B2 to B3. Then make the centre of the Star by matching these windings: L1 to A1, L2 to A2 and L3 to A3.

Connect the Delta windings as B1 to A2, B2 to A3, B3 to A1. Then connect L1 to A1, L2 to A2 and L3 to A3.

Tighten the windings onto the labelled screw terminals with a screwdriver.


Other 3-phase motors label windings differently than the Star Delta. For example, the windings might have the labels 1A, 1B, 1C, 2A, 2B and 2C.


If in doubt of how to read the labels of the windings, consult with a licensed electrician.

Things You'll Need

  • Wire stripper
  • Screwdriver set
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About the Author

Tammy Bronson has been a freelance writer since 1994. As a writer for Thompson Gale Publishing she wrote autobiographies and legal reviews. With Bronson wrote innovative informative articles about colleges and universities nationwide. She lives in the Greater Boston Area and has a Master of Arts degree in literature and writing from the State University of New York.