The Siemens SIRIUS 3RH1911-1HA12-ZW98 is a 4-pole auxiliary switch block with a 22 E contact configuration — 1 normally open and 2 normally closed contacts — designed for snap-on mounting onto contactors and contactor relays in the SIRIUS family. It uses screw-type terminals for the auxiliary and control circuit connections.
The block carries a maximum continuous current of 10 A, but the real-world switching capacity is voltage-dependent across both AC and DC loads. At 24 V AC/DC it is rated 6 A; at 60 V it drops to 2 A; at 110 V it is 1 A; at 220 V it is 0.3 A. For DC-12/DC-13 duty the 24 V rating is 10 A, derating to 4.7 A at 60 V, 3 A at 110 V, 1.2 A at 220 V, 0.5 A at 440 V, and 0.26 A at 600 V. At AC-15 at 690 V the rating is 1 A. These are not a single '10 A' part — the voltage class of the controlled circuit directly governs which contact rating applies.
Snap-on mounting onto the contactor or contactor relay means no additional DIN-rail space is consumed — the block clips directly onto the front of the base device. Dimensions are 36.5 mm wide, 37.5 mm high, and 41.5 mm deep, so it stays within the envelope of a size S00 contactor. Wire range accepts 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²) with core-end processing, or 2x (20 to 16) and 2x (18 to 14) AWG for auxiliary contacts.