The 3RH2916-1XA22-0MA0 is a Siemens SIRIUS auxiliary switch block that mounts on the front of 3RT2 contactors and 3RH2 contactor relays, adding four auxiliary contacts (2 NO + 2 NC) with screw-type terminals. It snaps onto the contactor or relay without tools, so it integrates directly into a DIN-rail panel layout — no extra brackets or wiring space needed beyond the contactor footprint.
The contacts are rated for a maximum of 10 A, but the real-world switching capacity depends on the voltage and duty. At 24 V the contacts handle 6 A; at 230 V they still carry 6 A; at 400 V the rating drops to 3 A. This means the same block works across control and light power circuits, but you need to check the voltage-specific limit for your load — especially at higher voltages where the current capability falls off. For AC-15 duty (solenoid and contactor coils), the contacts are rated 1 A at 690 V, which covers most industrial control circuits in 400 V or 480 V panels. The insulation is rated 690 V with pollution degree 3, and surge voltage resistance is 6 kV — typical for industrial environments where the switchgear sees transient spikes from motor starts or nearby lightning.
Reliability and service life
Mechanical service life is 1 million operating cycles typical, and contact reliability is specified at 1 faulty switching per 100 million operations at 17 V, 1 mA — that low-energy reliability matters for PLC inputs or dry-contact signals where oxide films on the contacts can cause intermittent opens.