SIRIUS auxiliary contactor, size S00 — 3 NO, 10 A
The Siemens 3RH1131-1BE40 is a SIRIUS auxiliary contactor in size S00, providing three normally-open (3 NO) instantaneous contacts for control-circuit switching. Rated at 10 A at 24 V (AC-12 maximum 10 A), it handles pilot-duty loads, PLC outputs, and relay coils within a control cabinet. The 6 kV surge voltage resistance gives it a solid margin for industrial environments with switching transients.
Wire termination and panel fit
Terminals accept solid conductors: 2x (0.5...1.5 mm²), 2x (0.75...2.5 mm²), or 2x 4 mm² per clamp. Spring-cage or screw terminals? The spec shows solid wire only — use ferruled stranded at the larger cross-sections to avoid whisker issues. Depth of 72 mm leaves clearance for wiring ducts and gland plates in shallow enclosures. The IP20 front protection means it's intended for enclosed panels, not open washdown areas.
Switching capacity across voltages
The 3RH1131-1BE40's contact ratings drop with voltage: 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, 2 A at 500 V, and 1 A at 690 V. For a 110 V control circuit it delivers 1 A; at 220 V it's 0.27 A. This derating curve follows the AC-12 resistive load profile — don't assume the 10 A holds at higher voltages.