The Siemens 3RT1916-2DH31 is a SIRIUS timing relay with an OFF-delay function — meaning the output stays energized for a set period after the control signal drops. The adjustable time range spans 5 to 100 s, set via a front-panel potentiometer or DIP switches (the evidence confirms it's adjustable, not fixed). Output is semiconductor-based, so it switches silently and handles high cycle rates without contact wear. Supply is universal: 90-240 V AC at 50 or 60 Hz, or 90-240 V DC, which simplifies panel wiring across mixed-voltage plants.
Dimensions are compact: 45 mm wide, 38 mm deep, 38 mm high, so it occupies a single modular unit on the rail. Any mounting position is allowed, which helps in tight enclosures where orientation is constrained. The IP20 rating on the terminals means finger-safe touch protection but no washdown tolerance — keep it inside a sealed panel, not on the wet side of a food line.
Electrical and environmental ratings
Basic insulation is standard for control circuits not directly connected to mains. The relay meets EN 61000-6-2, the generic immunity standard for industrial environments, so it's unlikely to nuisance-trip from nearby VFDs or contactors. Vibration resistance is 0.35 mm at 10-55 Hz; shock is 11 g for 15 ms — robust enough for most machine-mounted panels. Storage and transport temperature range is -40 to +85 °C; operating humidity is 15-95 % non-condensing.
Timing performance and repeatability
Relative repeat accuracy is 1 % — for a 10 s delay, that's ±0.1 s from cycle to cycle, consistent enough for conveyor sequencing or pump-off delays. Minimum ON period is 35 ms, meaning the relay needs at least that long of a control signal to recognize the start command. Recovery time after an output cycle is 150 ms before it can accept another trigger. The initial value upon power-up is 0.8 — this likely sets the delay to 80 % of the dialed value on first application, a detail to verify in the manual if your sequence depends on the first-cycle timing.