Three-phase motors wiring diagrams and markings of terminals
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.
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
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
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.