Overview
Siemens 3RA1924-2B is a side-mounted mechanical interlock accessory designed for reversing starter configurations. It provides snap-on mechanical interlock assembly for 3RT contactors in frame sizes S0 to S3, with 1 NC (normally closed) contact for each contactor. The unit is rated for lateral mounting with one auxiliary contact (1 NC per contactor) for sizes S0, S2, and S3.
Key Features
- Mechanical Interlock Design: Prevents simultaneous contactor closure, critical safety feature for reversing motor starters.
- Snap-On Lateral Mounting: Side-mount configuration for easy installation on 3RT contactor frames.
- Single Auxiliary Contact: Includes 1 NC contact for each contactor for control circuit feedback and interlocking logic.
- Frame Size Compatibility: Fits S0, S2, and S3 contactor sizes.
- Proven Industrial Standard: Part of Siemens’ 3RA1 product family, widely deployed in motor control applications.
Technical Specifications
- Part Number: 3RA1924-2B
- Manufacturer: Siemens
- Product Type: Mechanical Interlock with Auxiliary Contact Block
- Mounting Style: Lateral (Side-Mount)
- Compatible Contactor Sizes: S0, S2, S3
- Auxiliary Contacts: 1 NC (Normally Closed) per contactor
- Contact Type: Normally Closed (NC)
- Net Weight: 61 grams (0.061 kg)
- Product Class: Standard stock item
- Status: Phased-out product; successor is SIRIUS 3RA2
Typical Applications
- Reversing motor starter assemblies for three-phase AC motors
- Forward-reverse control circuits requiring mechanical interlocking
- Industrial motor control panels and soft-starter configurations
- HVAC, pump, and compressor motor applications
- Machinery requiring bidirectional motor control with safety interlock
Compatibility & Replacements
Compatible With
- Siemens 3RT10, 3RT11 contactors (frame sizes S0, S2, S3)
- Siemens 3RT reversing starter assemblies
- Standard 24 VDC and 110/240 VAC motor control circuits
- Mechanical interlocking reversing starter configurations
Replaces / Drop-In Replacement For
Verify compatibility with your system integrator before ordering. This unit is a direct replacement for OEM Siemens 3RA1924-2B applications.
Works With
- Siemens SIRIUS motor control equipment
- Standard 3-phase AC motor circuits
- Electromechanical relay and PLC-based control systems
- Industrial control panels following IEC 60947 standards
