The Siemens 3RH2344-1CN20 is a SIRIUS auxiliary contactor, size S00, with 4 normally-open instantaneous contacts. It's the switching block that extends the signal-routing capacity of a main contactor or starter — think of it as the relay that tells the PLC 'the motor contactor has pulled in' or that sequences a downstream solenoid. Rated insulation voltage goes to 690 V, so it lives comfortably in 400 VAC panels. The housing is 45 mm wide, 57.5 mm tall, 117 mm deep — that's a compact footprint for a 4-pole block, and it shares the S00 envelope with the matching 3RT2 contactors.
Each NO contact is rated for 10 A at 24 V, 6 A at 230 V, 3 A at 400 V, and 1 A at 690 V — the thermal current follows the usual inverse curve as voltage climbs. At 24 VDC the contacts handle 10 A; at 60 VDC that drops to 4.7 A, and at 220 VDC it's 1.2 A. The arcing time sits between 10 and 15 ms, which is typical for an AC coil contactor of this size. For DC switching at higher voltages, watch the make/break energy — the 0.26 A at 600 VDC tells you this isn't a DC load-break monster; it's sized for control signals and small solenoids. The contacts are instantaneous — no timing delays, no overlap adjustment. That makes them a straight choice for feedback to a PLC input or for interlocking where you need the contact to follow the armature position exactly.
Environmental and compliance details
The minimum relative humidity is 10 %, so dry climates or heated cabinets aren't a problem.