Siemens 3RA1973-2B Wiring Kit for SIRIUS Star-Delta Starter S12, Link Rails & Neutral Bridge for 3RT1.7 Contactors Original Brand New

Overview

The Siemens 3RA1973-2B Link Rail Set is an essential wiring kit accessory for constructing a robust SIRIUS Star-Delta (Wye-Delta) Starter assembly with size S12 contactors. This complete set is specifically engineered to create the internal power connections between the main delta contactor and the star (wye) contactor, both being the 3RT1.7 series, simplifying the installation process.

It includes all necessary link rails, a set of connection screws, and the crucial neutral bridge. Designed for contactors with a busbar connection (without box terminal), this kit also features phase swapping on the outgoing side to ensure correct operation of the star-delta configuration. Upgrade your motor control system with this genuine Siemens component for reliable, professional-grade connections.

Technical Specification

• Manufacturer: Siemens
• Product Number (MLFB): 3RA1973-2B
• Product Designation: Wiring kit / Link Rail Set
• Contactor Size: S12
• Contactor Series Compatibility: SIRIUS 3RT1.7
• Application: Star-Delta (Wye-Delta) Starter Assembly
• Connection Method: Busbar Connection (Without Box Terminal)
• Features: Includes set of connection screws, phase swapping on outgoing side, neutral bridge.
• Number of Poles: 3-pole
• Product Group: 3729

Key Benefit

1. Guaranteed Compatibility: Specifically engineered for the seamless connection of Siemens 3RT1.7 delta and star (wye) contactors in a size S12 star-delta configuration.
2. Reduced Assembly Errors: The pre-designed link rail set minimizes wiring complexity, significantly reducing installation time and the risk of incorrect connections.
3. Optimized Motor Starting: Facilitates the preferred star-delta (wye-delta) switching method, which is known to reduce starting current to approximately $1/3$ of the direct-on-line current and minimizes transient current peaks during the star-to-delta switchover.
4. Enhanced Reliability: Ensures the precise phase swapping on the outgoing side as required for proper star-delta operation, which contributes to preventing equipment damage and ensuring long-term operational reliability.
5. Professional Busbar Integration: Designed for contactors utilizing a busbar connection, offering a tidy, robust, and high-quality connection solution, eliminating the need for bulky box terminals.

Function and Application

The 3RA1973-2B link rail set is an accessory for the SIRIUS modular system, critical for building a complete star-delta starter for squirrel-cage motors.

• Function: It serves as the pre-formed, conductive link between the main (delta) contactor and the star (wye) contactor, handling the phase-to-phase and phase-to-neutral connections, including the essential phase swapping on the motor-side output terminals (U2, V2, W2) of the contactors. The inclusion of the neutral bridge ensures the proper configuration for the star point during the star phase.
• Application: Used in industrial automation and motor control applications for starting large motors where reducing the high starting current is necessary to protect the motor, electrical supply, and mechanical drive system.

For more of our high-quality industrial automation and control products, visit turll today!