Overview
The Siemens 3RH1122-1BB40 is a compact auxiliary contact block designed for integration with SIRIUS contactors and control relays. This 2NO/2NC (2 normally open, 2 normally closed) block operates on 24VDC control voltage and delivers 10A switching capacity per contact. Engineered for industrial control applications, the 3RH1122-1BB40 provides reliable auxiliary switching with proven IEC compliance and extends the functionality of existing contactor installations.
Key Features
- 4-pole IEC control relay with fixed contacts
- 2NO + 2NC contact configuration for diverse switching logic
- 24VDC coil rated at 10A auxiliary circuit capacity
- Frame size S00 for compact DIN rail mounting
- Screw-type terminals for secure auxiliary and control circuit connections
- Snap-on or screw mounting compatibility with SIRIUS control modules
Technical Specifications
The auxiliary block incorporates proven switching reliability with minimal contact wear. DC operating range spans 0.8–1.1 times rated coil voltage, ensuring stable performance across typical industrial supply fluctuations.
Typical Applications
- Motor control center (MCC) auxiliary signaling and status feedback
- Pump, fan, and compressor start/stop interlocking logic
- Machine automation with multi-state control sequences
- Building HVAC and conveyor system control circuits
- Process equipment enabling/disabling and limit switching
Compatibility & Replacements
The 3RH1122-1BB40 is designed as a direct plug-in accessory for Siemens SIRIUS modular contactors and industrial relays. It mounts via snap or screw connection to compatible base units. This auxiliary block integrates seamlessly into existing control cabinets without major rewiring, making it an efficient retrofit or expansion solution for production environments requiring additional switching logic.
