Auxiliary contactor, size S00, 3-pole
The Siemens 3RH2131-1BP40 is a SIRIUS auxiliary contactor in the S00 frame size, carrying three instantaneous contacts (NO/NC configurable per wiring) and a 230 V AC coil. This is the part you reach for when the main contactor's auxiliary blocks are full and you need to mirror a status signal or interlock a sequence without adding a second main contactor.
DIN rail footprint and panel clearance
Width 45 mm, height 57.5 mm, depth 73 mm. The 10 % relative humidity minimum matters for long-term storage in unconditioned warehouses.
Coil draw and contact performance
Closing power of the magnet coil at DC is 4 W; holding power at DC is also 4 W — a constant-gap design that doesn't spike inrush. The DC switching time is 7 to 13 ms. Mechanical service life is 30,000,000 operations typical — this is the S00 frame's standard endurance. The product extension for auxiliary switches is available — you can add side-mount blocks if the three built-in contacts aren't enough.
RoHS compliance date is 10 January 2009 — the part meets the EU RoHS directive.