What this auxiliary switch does
The 3RT1926-2GJ51: Rated 3 A maximum, it handles control-circuit loads typical in 24 VDC panels. The switch is designed for star-delta starting circuits, meaning it can be wired into the transition sequence without extra isolation.
Clip-on fastening method — snaps directly onto the contactor without tools. The 33 mm width and 46 mm height keep the assembly within a standard DIN-rail footprint. Depth is 73 mm, which includes the terminal projection; account for this when spacing components in the enclosure. Mounting position is any orientation, so it fits horizontal or vertical bus arrangements without derating.
Switching ratings and wiring
At 24 VDC the switch is rated 1 A; at 125 VAC it handles 0.2 A, and at 250 VAC it handles 0.1 A. These are the contact ratings for the control circuit — stay within them to avoid welding the silver-alloy contacts. Wire range accepts solid or stranded 18–14 AWG (2x 20–14 AWG for solid), which covers most panel control wiring.