Solid-state-compatible NO and contact reliability at low level
The 3RH2911-2NM22-0MC0 is a front-mounted auxiliary switch block for Siemens S00, S0, S2, and S3 contactors. Its contact set is 2 NO + 2 NC, with one NO specifically rated as solid-state-compatible — that means it's designed to switch the low-side leakage currents of a solid-state output without welding or failing to open, a common failure point when a standard relay contact tries to interrupt a triac's off-state current. That's the contact reliability floor — if your PLC input or safety relay expects a dry circuit signal at low voltage, this block won't bounce into an open state.
Spring-loaded terminals and snap-on DIN rail mount
No screw torque to check, no loosening under vibration — the cage clamps the conductor and holds. Snap-on mounting to DIN rail. The block measures 36 mm wide by 47.7 mm deep by 41.5 mm high — it sits flush on the contactor's front face, not stealing extra panel depth. Front protection is IP20 — finger-safe when installed, but no washdown rating. Keep it inside the enclosure.
Control circuit draw and surge withstand
The auxiliary coil or signal circuit draws 0.3 A at 24 V, 48 V, or 60 V — the same current across all three voltages, which suggests an internal current-limiting circuit rather than a simple coil. Budget that draw into your 24 VDC supply sizing; it's not a relay coil inrush. Rated surge voltage resistance is 6 kV, and insulation voltage at pollution degree 3 is 690 V AC. That covers most 400 V line-to-line panels with margin.
Sourced to order against the BOM quantity.