S00 frame coupling relay for auxiliary circuit isolation
The 3RH2131-2LB40-1AA0 is a SIRIUS coupling relay in the S00 frame size — the smallest contactor chassis in the Siemens industrial controls family, sized for auxiliary circuits rather than main motor power. Its three instantaneous NO contacts switch 10 A at both 24 V and 230 V rated values, covering DC-13 solenoid loads and AC-15 contactor coils in the same device. The 24 VDC coil draws 2.8 W closing power and includes a built-in varistor surge suppressor, eliminating the need for an external flyback diode or RC snubber across the coil terminals.
Panel fit and clearance planning
Minimum clearances of 10 mm upwards, forwards, and downwards, plus 6 mm at the side, must be maintained to adjacent devices for arc flash containment and cooling airflow.
Switching performance and environmental limits
Mechanical service life is 30,000,000 operations typical, meaning the contact wear mechanism — not the coil or armature — sets the replacement interval in high-cycle applications. Pollution degree 3 rating confirms suitability for industrial enclosures where conductive dust is present.
Sourced through the authorized Siemens channel; quantities are quoted to order against the BOM with full factory traceability and warranty.