Overview
The Siemens 3RH1921-1EA02 is a first lateral side-mounted auxiliary contact block engineered for integration with the SIRIUS 3RT1 family of IEC-rated motor contactors. This compact contactor accessory provides two normally closed (2NC) contact sets with instantaneous response, enabling precise auxiliary control and status monitoring in industrial motor control applications. Built to German standards, it delivers reliable switching performance across millions of operating cycles.
Key Features
- 2 normally closed (NC) contacts with instantaneous switching
- Snap-on side-mount design for tool-free installation on 3RT1 contactors
- Screw terminals for secure wire connections
- Rated for contactor sizes S0 through S12
- IP20 protection class on front mounting surface
- IEC 60947-5-1 compliant auxiliary switch
Technical Specifications
The 3RH1921-1EA02 meets stringent industrial automation requirements:
- Insulation voltage: 500 V AC (degree of pollution 3)
- Surge voltage resistance: 6 kV rated
- Mechanical service life: 10,000,000 operating cycles (typical)
- Electrical endurance at AC-15 (230 V): 200,000 operating cycles (typical)
- Contact rating: 20–14 A section
- Net weight: 0.05 kg
- Mounting: First lateral side-mount position
Typical Applications
The 3RH1921-1EA02 is commonly deployed in:
- Motor soft-start and motor protection circuits
- Interlocking and permissive control logic
- Status indication and pilot device feedback
- Industrial machinery and factory automation systems
- HVAC and pump control panels
Compatibility & Replacements
This auxiliary switch block is designed as a drop-in accessory for Siemens 3RT1 contactors—including 3RT10, 3RT12, 3RT145, 3RT146, and 3RT147 models in sizes S0–S12. If your system requires 2 normally open (NO) contacts instead, the 3RH1921-1EA20 is the equivalent NC variant. Always verify contactor size and mounting position before ordering to ensure proper mechanical fit and electrical performance.
