Auxiliary contactor for control-circuit switching — 42 V DC coil, 4 NO, size S00
The Siemens 3RH2140-1BD40 is a SIRIUS auxiliary contactor in frame size S00, designed for switching control circuits in industrial panels. Its 42 V DC coil draws 4 W during both closing and holding, a low burden on the control transformer that simplifies thermal budgeting in multi-contactor assemblies. The contactor provides 4 normally-open instantaneous contacts, each rated for switching at voltages from 24 V to 690 V AC/DC. Mechanical service life is 30,000,000 operations typical, supporting high-cycle applications such as conveyor interlocking or press control sequences where the auxiliary contactor sees every machine cycle.
Panel fit and mounting — 45 mm wide, DIN-rail snap-on, flexible orientation
Width is 45 mm, height 57.5 mm, depth 73 mm — the 45 mm width is the critical panel-space dimension when ganging multiple contactors side by side. Degree of pollution 3 means the contactor is rated for environments where conductive pollution occurs — typical in industrial panels without climate control where dust and condensation may be present.
Switching performance and environmental limits
At DC the switching rate is bounded by the 7-13 ms on-time. These figures govern how fast the contactor can follow a PLC output sequence without exceeding thermal limits. Relative humidity minimum 10 % — the contactor tolerates dry environments common in switchgear rooms without condensation risk. The dual-wire entry allows daisy-chaining control wiring without additional terminal blocks.
Compliance and substance restrictions
Substance prohibitance date is 10/01/2009, aligning with RoHS compliance requirements. The product extension auxiliary switch is available (Yes), allowing field addition of extra contact blocks without replacing the base contactor.