OFF-delay timer for SIRIUS contactor assemblies
The Siemens 3RA2812-1DW10 is a SIRIUS function module that adds an adjustable OFF-delay to a contactor or motor starter assembly. It clips directly onto the contactor, so no extra DIN-rail space or wiring is needed for the timing function. The delay is adjustable from 0.05 to 100 seconds, and the control supply accepts 24-240 V AC/DC — one part covers both 24 V and 230 V control circuits across 50/60 Hz.
What the OFF-delay means in a panel
An OFF-delay (also called delay-on-break) keeps the contactor closed for a set time after the control signal is removed. This is useful for sequenced shutdowns — a fan running after the chiller stops, or a conveyor holding position until downstream gates clear. The module mounts in any position (like the contactor it clips to) and operates from -25 to +60 °C, so it works inside a warm panel without derating. Recovery time is 50 ms — the module resets fast enough for repeated start/stop cycles in a packaging or material-handling line.