Connection diagram for three-phase Motors

The windings of the motors can be connected in two ways:
• Star connection
• Delta connection

Star connection:

The star connection is obtained by connecting together the W2, U2, V2 terminals and supplying the terminals U1, V1, W1.
The current and voltage phase are:

Iph = In
UPH = Un / Ö 3

where "In" is the line current and "Un" the line voltage.

Delta Connection:

The Delta connection is obtained by connecting the end of one phase at the beginning of the next phase.
The current and voltage phase are:

IPH = In / Ö 3

Uph = Un

Connection for Star-Delta starting:

Star-Delta starting is the easiest way to reduce the current and the starting torque. Motors whose rated voltage with delta connection match to the mains voltage can start with the star-delta method. From size 132, the motors are supplied as standard with windings designed for this starting method (example: 400V Delta / 690V Star).

Connection in two speed motors:

When the ratio between the two speeds is 1:2, standard motors have a single winding (Dahlander connection). For other speeds motors have two separate windings.