Three-phase motors wiring diagrams and markings of terminals

Direction of rotation and markings of terminals Three-phase motors - TESLA Institute 

 

The windings are connected in star (Y) -connection or in delta (Δ)-connection according to IEC 60034-8. This is done by wiring the terminal board as shown in the wiring diagram to the right. The marking of the terminal board is also defined in IEC 60034-8.

 

 

Direction of rotation and markings of terminals Three-phase motors 02 TESLA Institute

 

Star (Y) - connection

 

By short-circuiting the terminals W2, U2 and V2 and connecting the mains to the W1, U1 and V1 you get a star(Y) - connection.

 

Current: Iphase = Imains

 

Voltage: Uphase = Umains / √3

 

Direction of rotation and markings of terminals Three-phase motors 03 TESLA Institute

 

Delta (Δ) - connection

 

When connecting the end of a phase to the start of another phase you get a delta(Δ) - connection

 

Current: Iphase = Imains / √3

 

Voltage: Uphase = Umains

 

Direction of rotation and markings of terminals Three-phase motors 04 TESLA Institute

 

The direction of rotation for the motor shaft is defined in IEC 60034-8 as either CW (clockwise) or CCW (counter-clockwise), when looking into the shaft.

The direction of rotation can be changed at the terminal board. When dealing with a threephase motor, this is done by interchanging two of the line cables, eg.: switch L1 and L2.

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