Adjustable ON-delay 0.5...10 s — what it means for the circuit
The 3RT1926-2FL21 is a SIRIUS auxiliary switch with an adjustable ON-delay timer covering 0.5 to 10 seconds. That range covers most sequence-start and staggered-pickup applications on a contactor rail — think staging multiple motor starters so they don't all hit the line at once. It clips onto a 3RT1 contactor (the standard SIRIUS footprint), so no extra DIN-rail space or wiring is needed. The delay is set by a potentiometer on the face — no software, no programming module.
Contact ratings — 3 A max, derated by voltage
The switch contacts are rated 3 A maximum, but the real-world current depends on the control voltage: 1 A at 24 V, 0.2 A at 125 V, and 0.1 A at 250 V. That's typical for an auxiliary contact block — sized for PLC inputs, contactor coils, and signal lamps, not power loads. The minimum ON period is 200 ms, and the recovery time between cycles is 150 ms. If the control signal pulses shorter than that, the timer won't latch.
Clip-on mounting, any position, -25 to +60 °C operation
Fastening is clip-on — it snaps directly onto the front of a 3RT1 contactor without tools. Mounting position is any, which helps in tight panels where the contactor is sideways or upside-down. The insulation is basic, pollution degree 3, so it's fine for standard industrial control panels but not for wet or conductive-dust environments without an enclosure. Dimensions are 73 mm deep, 33 mm wide, 46 mm tall — the width matches the contactor profile so it doesn't overhang.