What the ratings mean for your circuit
The 3RH2911-4HA10: This auxiliary switch carries a 10 A rated operational current at AC-12 (resistive loads) and 6 A at 24 V DC — that 6 A figure at 24 V is the one to check if you're switching DC solenoids or PLC inputs, because DC arcs don't self-extinguish like AC and the contact gap is sized for it. At higher DC voltages the current drops fast: 2 A at 48 V and 60 V, 1 A at 110 V, 0.3 A at 220 V, and 0.26 A at 600 V — so if your control voltage is 125 VDC you're limited to 0.9 A per contact. For AC-15 duty (solenoid and electromagnetic loads) at 690 V the rated current is 1 A — this is the category that matters when the switch feeds contactor coils or valve solenoids in a motor control center.
Mirror contact and safety circuit fit
This switch is a mirror contact per IEC 60947-4-1 when used with the 3RT2 contactor — that means the NO and NC contacts are mechanically linked so they can't both be closed at the same time, which is the requirement for safety-related feedback circuits in a Category 3 or 4 structure per ISO 13849-1. The contact reliability spec says one faulty switching per 100 million operations at 17 V and 1 mA — that low-level wetting current matters if you're switching dry logic inputs where the contact film doesn't burn off; below 1 mA you'd want a gold-plated contact block instead.
Panel fit and mounting
Snaps onto the front of SIRIUS contactors in sizes S00, S0, S2, and S3 — the same auxiliary switch block fits across that whole frame range, so you can standardize one spare part number for different contactor sizes in the panel. Dimensions are 36 mm wide by 43.7 mm deep by 37.5 mm tall — the width matches the S00/S0 contactor width, so it doesn't overhang the contactor envelope on the DIN rail. Termination is ring terminal lug connection — not cage clamp or screw clamp — so you'll need ring lugs crimped onto your control wiring; factor that into the wire prep step if your panel shop is used to push-in terminals.
Lifecycle and sourcing reality
It carries a single NO instantaneous contact (no lagging or leading contact variants) — the 1 NO configuration is the most common for feedback or enable circuits; if you need 1 NC or 2 NO you're looking at a different order code in the 3RH29 family.