The 3RA24 contactor assemblies for star-delta (wye-delta) starting are designed for standard applications.

Note:

Contactor assemblies for star-delta (wye-delta) starting in special applications such as very heavy starting or star-delta (wye-delta) starting of special motors must be customized. Help with designing such special applications is available from Technical Assistance.

Phone: +49 (911) 895-5900

E-mail: technical-assistance@siemens.com.

For effective support from Technical Assistance you must provide the following details:

• Rated motor voltage
• Rated motor current
• Service factor, operating values
• Motor starting current factor
• Ramp-up time
• Ambient temperature

The 3RA24 contactor assemblies for star-delta (wye-delta) starting can be ordered as follows:

Sizes S00 to S2:

• Fully wired and tested, with electrical and mechanical interlock
• All individual parts for customer assembly, see "Accessories and Spare Parts" > "for SIRIUS 3RT2 Contactors and SIRIUS 3RH2 Contactor Relays".

A dead interval of 50 ms on reversing is already integrated in the 3RA28 function module for star-delta (wye-delta) starting.

The 3RA24 contactor assemblies for star-delta (wye-delta) starting have screw or spring-type terminals and are suitable for screwing or snapping onto TH 35 standard mounting rails. A base plate is also available for the size S2 assembly.

With the fully wired and tested 3RA24 contactor assemblies for star-delta (wye-delta) starting, the auxiliary contacts included in the basic devices are unassigned.

Complete units

Note:

The selection of contactor types refers to fused designs.

SIRIUS 3RA28 function module for star-delta (wye-delta) starting

The 3RA2816?0EW20 function module replaces the complete wiring in the control circuit and can be used in the voltage range from 24 to 240 V AC/DC. It is snapped onto the front of the contactor assembly for star-delta (wye-delta) starting, size S00, S0 or S2.

One function module comprises a complete module kit:

• Basic module with integrated control logic and time setting
• Two coupling modules with corresponding connecting cables

The scope of supply thus comprises a complete module kit for one contactor assembly for star-delta (wye-delta) starting, size S00, S0 or S2, regardless of the connection method.

Data of the control circuit

• Wide voltage range 24 to 240 V AC/DC
• Time setting range 0.5 to 60 s (3 selectable settings)
• Dead interval of 50 ms, non-adjustable

Surge suppression

Surge suppression (varistor) is included in the function modules for star-delta (wye-delta) starting.

Motor protection

3RU21 or 3RB3 overload relays for contactor mounting or stand-alone installation can be used as overload protection, (see “Protection Equipment" > "Overload Relays") or 3RN1 thermistor motor protection evaluation units (see "Monitoring and Control Devices" > "Relays" > "SIRIUS 3RN1 Thermistor Motor Protection") and 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.

Components for customer assembly

Assembly kits with wiring modules and mechanical connectors are available for contactor assemblies for star-delta (wye-delta) starting. Contactors, overload relays, function modules for star-delta (wye-delta) starting or wye-delta timing relays, auxiliary switches for electrical interlock – if required also infeed terminals and base plates – must be ordered separately.

Accessories, see "Accessories and Spare Parts" > "for SIRIUS 3RT2 Contactors and SIRIUS 3RH2 Contactor Relays".

The wiring kits for sizes S00 to S2 contain the top and bottom main conducting path connections between the line and delta contactors (top) and between the delta and star contactors (bottom).

¹⁾ The assembly kit S00-S00-S00 contains: Mechanical interlock, four connecting clips; wiring modules on the top (connection between line and delta contactor) and on the bottom (connection between delta and star contactor); star jumper and auxiliary circuit wiring. Accessories, see "Accessories and Spare Parts" > "for SIRIUS 3RT2 Contactors and SIRIUS 3RH2 Contactor Relays" > "Miscellaneous".

²⁾ The assembly kit (S2-S2-S0) contains: Two connectors, wiring modules on top and bottom (S2-S0) for the main circuit, an S0 star jumper, a spacer and a cable set for the auxiliary circuit, and a cable for connecting the A2 coil contact from the line contactor to the A2 coil contact of the delta contactor. The 3RA2934-2B mechanical interlock must be ordered separately. Accessories, see "Accessories and Spare Parts" > "for SIRIUS 3RT2 Contactors and SIRIUS 3RH2 Contactor Relays" > "Miscellaneous".

³⁾ The assembly kit (S2-S2-S2) contains: Four connectors, wiring modules on the top and bottom for the main circuit and the auxiliary circuit, an S2 star jumper and a cable for connecting the A2 coil contact from the line contactor to the A2 coil contact of the delta contactor. The 3RA2934-2B mechanical interlock must be ordered separately. Accessories, see "Accessories and Spare Parts" > "for SIRIUS 3RT2 Contactors and SIRIUS 3RH2 Contactor Relays" > "Miscellaneous".

⁴⁾ The assembly kit (S00-S00-S00) contains: Mechanical interlock, four connecting clips; wiring modules on the top (connection between line and delta contactor) and on the bottom (connection between delta and star contactor); star jumper. Accessories, see "Accessories and Spare Parts" > "for SIRIUS 3RT2 Contactors and SIRIUS 3RH2 Contactor Relays" > "Miscellaneous".

⁵⁾ The assembly kit (S2-S2-S2) contains: Four connectors, wiring modules on the top and bottom for the main circuit, an S2 star jumper, a cable set for the auxiliary circuit and a cable for connecting the A2 coil contact from the line contactor to the A2 coil contact of the delta contactor. The 3RA2934-2B mechanical interlock must be ordered separately. Accessories, see "Accessories and Spare Parts" > "for SIRIUS 3RT2 Contactors and SIRIUS 3RH2 Contactor Relays" > "Miscellaneous".

Article No. scheme

Note:

The Article No. scheme is presented here merely for information purposes and for better understanding of the logic behind the article numbers.

Fully wired and tested contactor assemblies for star-delta (wye-delta) starting · Size S00-S00-S00 · Up to 11 kW

The figure shows the version with screw terminals

Complete contactor assemblies for star-delta (wye-delta) starting, see Ordering data.

Note:

When using the function modules for contactor assemblies for star-delta (wye-delta) starting, no other auxiliary switches are allowed to be connected to the basic units.

Fully wired and tested contactor assemblies for star-delta (wye-delta) starting · Size S0-S0-S0 · Up to 22 kW

The figure shows the version with screw terminals

Complete contactor assemblies for star-delta (wye-delta) starting, see Ordering data.

Note:

When using the function modules for contactor assemblies for star-delta (wye-delta) starting, no other auxiliary switches are allowed to be connected to the basic units.

Fully wired and tested contactor assemblies for star-delta (wye-delta) starting · Size S2-S2-S0¹⁾ · Up to 45 kW and S2-S2-S2 · 55 kW

The figure shows the version with screw terminals in S2-S2-S2

¹⁾ Complete contactor assembly for star-delta (wye-delta) starting in size S2-S2-S0 (not shown): The 3RA2933-2C assembly kit is to be used here. It contains two connectors for three contactors, an S0 star jumper, a spacer, wiring modules on the top and bottom (S2-S0) for the main circuit, a cable set for the auxiliary circuit, and a cable for connecting the A2 coil contact from the line contactor to the A2 coil contact of the delta contactor The 3RA2934-2B mechanical interlock for size S2 must be ordered separately. Accessories, see "Accessories and Spare Parts" > "for SIRIUS 3RT2 Contactors and SIRIUS 3RH2 Contactor Relays" > "Miscellaneous".

Complete contactor assemblies for star-delta (wye-delta) starting, see Ordering data.