What it is and what it does
The Siemens SIRIUS 3RT1916-2BK01 is an OFF delay device — a pneumatic or electronic timer that holds the contactor closed for a set period after the control signal drops, then releases. It mounts directly onto 3RT10 contactors in sizes S00 and S0, and onto 3RH contactor relays with DC operation, using the same screw and snap-on mounting onto 35 mm standard DIN rail per EN 50022. Control voltage is 110-127 V AC/DC, meaning it accepts either AC or DC supply across that range — useful when the control circuit is mixed or being migrated. The screw-type terminals on the auxiliary and control circuit accept solid or ferruled stranded conductors, and the housing is finger-safe for protection against accidental contact during panel work. Rated for operation from -20 to +60 °C and storage from -40 to +80 °C, so it handles the thermal range inside a standard IP20 control cabinet without derating concerns. Mounting position is any orientation, which simplifies layout in crowded enclosures.
Panel integration and fit
Mounts directly onto the contactor's front face — no additional DIN rail space required. The snap-on mechanism engages with the contactor housing; screw terminals are then wired per the control schematic. The finger-safe design means no additional shrouding is needed for the terminals inside an IP20 enclosure.