SIEMENS 西门子SIRIUS 3RA24 contactor assemblies for star-delta (wye-delta) starting, up to 90 kW

The 3RA24 contactor assemblies for star-delta (wye-delta) starting in sizes S00 to S3 can be ordered as follows:

• 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".

The 3RA24 contactor assemblies for star-delta (wye-delta) starting have screw or spring-type terminals and are suitable for screw and snap-on mounting onto TH 35 standard mounting rails.

A base plate is also available for the size S2 and S3 assemblies.

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

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

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 starting1) or star-delta (wye-delta) starting of special motors must be customized. Help with designing such special applications is available from our Technical Support:
https://support.industry.siemens.com/My/ww/en/requests.

1) For effective support from Technical Support you must provide the following details:
- Rated motor voltage,
- Rated motor current, 
- Service factor, operating values
- Motor starting current factor
- Starting time,
- Ambient temperature.

Surge suppression

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

Motor protection

For motor protection, 3RU2 or 3RB3 overload relays for contactor mounting or stand-alone installation (see Overload Relays), SIMOCODE pro 3UF7 motor management and control devices or 3RN thermistor motor protection relays can be used.

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.

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, S2 or S3.

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, S2 or S3, 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

Complete units

Note:

The selection of contactor types refers to fused designs.