The Siemens 3RT2926-2PR01-0MT0 is a SIRIUS pneumatic timing relay block that clips onto a size S0 contactor and provides an adjustable OFF-delay of 0.1 to 30 seconds, with one normally-open and one normally-closed auxiliary contact. It switches loads at various control voltages — 4 A at 24 V, 6 A at 230 V, 4 A at 400 V, and 1.5 A at 690 V — so the same block works across 24 VDC control circuits and 400 VAC motor starters. The screw-type terminals accept 2x (0.5…1.5 mm²) solid or 2x (0.75…2.5 mm²) stranded, and the front face is IP20 finger-safe — safe to handle in an open panel without de-energizing the control circuit.
Clip-on fastening to a size S0 contactor (the 3RT2 series). No DIN rail needed — it snaps directly onto the contactor's front. Dimensions: 45 mm wide, 44.6 mm high, 83.5 mm deep. The depth includes the pneumatic actuator; make sure there's clearance in front of the contactor for the block to extend. Mechanical service life is 5 million switching cycles when mounted on a size S0 contactor.
The AC-12 maximum switching current is 10 A — that's the resistive-load rating for the contacts themselves, not the contactor's main poles. The off-delay accuracy is ±20 % of the set value, which is adequate for sequencing (conveyor overlap, fan run-down) but not for precision timing. Short-circuit protection for the auxiliary contacts requires a gG 10 A fuse rated for 1 kA at the prospective fault level per IEC 60947-5-1. Operating temperature range is 5…50 °C; storage range is -50…+80 °C. If the panel sees freezing temperatures at startup, the pneumatic delay may drift — the air viscosity changes with cold.