3TE6 contactor assemblies for star-delta (wye-delta) starting are suitable for use in any climate. They are finger-safe according to IEC 60529.

3TE6 contactor assemblies for star-delta (wye-delta) starting are available as complete units, and as components for customer assembly. They consist of two 3TF68 vacuum contactors, and the 3RT1075 contactor as the star (wye) contactor.

The complete unit combinations are optionally supplied without a main conducting path connection between the line contactor and the delta contactor.

Control circuit (auxiliary contacts)

The 3TF68 vacuum contactors have four lateral auxiliary switches, each with 1 NO + 1 NC contact. The following auxiliary contacts are required for the control circuit of the assembly:

• Line contactor Q1: 13-14, 43-44
• Star (wye) contactor Q2: 13-14, 21-22
• Delta contactor Q3: 13-14, 21-22

The star-delta (wye-delta) changeover is implemented via a lateral timing relay 3RP1574 (1 to 20 ms) or 3RP1576 (3 to 60 ms).

For the wiring of the individual contactors, see the circuit diagrams of the control circuits in the reference manual "Switching Devices - Contactors and Contactor Assemblies", https://support.industry.siemens.com/cs/ww/en/view/35554359.

Motor protection

3TE68 star-delta (wye-delta) contactor assemblies are supplied without overload protection. Overload relays or thermistor motor protection evaluation units must be ordered separately.

The overload relay can be either mounted onto the line contactor or separately fitted. It must be set to 0.58 times the rated motor current.