The Siemens 3RH2916-2FA22 is a front-mounted auxiliary switch block in the SIRIUS family, designed to snap onto 3RT2 contactors and 3RH2 contactor relays. It provides 2 normally-open and 2 normally-closed contacts, with the current paths arranged as 1 NO, 1 NC, 1 NC, 1 NO — a sequence that matters when you're wiring interlocking or feedback circuits and need to know which contact opens or closes first. Rated at 10 A maximum, the contacts are specified for both AC and DC switching across a wide voltage range. At 24 V AC the contacts carry 6 A; at 230 V AC they carry 6 A; at 400 V AC they carry 3 A. For DC loads at 24 V the rated current is 10 A, dropping to 0.26 A at 600 V DC. The AC-15 rating at 690 V is 1 A — that's the inductive load rating for solenoid and contactor coils, so this block is suited for pilot-duty switching in control circuits. Mechanical life is 1,000,000 operating cycles typical. Termination is via spring-loaded terminals, accepting 2x (0.5 to 1.5 mm²) with ferrule and 2x (0.5 to 2.5 mm²) without.
Panel Integration
Snap-on mounting directly onto the contactor or relay body — no DIN rail required for the switch block itself, though the base contactor mounts to DIN rail. The 36 mm width, 47.7 mm depth, and 41.5 mm height mean it adds minimal footprint to the contactor assembly. Verify the 3RT2 or 3RH2 base unit's auxiliary slot compatibility; this block occupies the front position. Spring-loaded terminals reduce wiring time compared to screw terminals — no torque driver needed, and the cage accepts solid or ferruled stranded wire. The 2x (20 to 14 AWG) range covers common control wiring sizes.