The 3RT2026-2KB40 is a coupling contactor for switching between control circuits or isolating panel sections.
The 24 V DC coil pulls in reliably across the operating temperature range of -25 to +60 °C, and storage tolerance goes from -55 to +80 °C — so it handles unheated warehouses or hot cabinets without issue. The coil connection uses spring-type terminals (rated for solid or stranded 1 to 10 mm²), which saves wiring time compared to screw terminals, especially in high-density panels. Main contact current ratings vary by duty: the 18 to 8 A range covers AC-1 through AC-4 loads. At 24 V DC the switching capacity is 10 A, dropping to 2 A at 48/60 V DC, 1 A at 110 V, 0.9 A at 125 V, and 0.3 A at 220 V — so if you're switching DC loads above 24 V, the current derating is significant. For AC motor loads at 230 V it's rated 3 hp, and at 400 V AC it handles 3 A. Mechanical life is typical 10 million operations, and the maximum switching frequency varies by duty: 1,000 cycles/hour at AC-1, 750 at AC-2/AC-3, and 250 at AC-4. Arcing time is 10 to 10 ms, and the coil pick-up/drop-out at DC is 19 to 21 ms — fast enough for most sequencing applications but not for precision timing.
The dimensions are 45 mm wide, 102 mm high, and 107 mm deep — so it occupies about the same footprint as a standard miniature circuit breaker. The contactor has no auxiliary switch built in (auxiliary switch is listed as "No"), so if you need feedback contacts for a PLC or status indication, you'll need to add a separate auxiliary contact block. The main contacts are rated for 2x (0.5 to 2.5 mm²) solid or stranded wire, and the coil terminals accept 1 to 10 mm² solid or stranded.
The closest functional sibling in the same S0 frame is the 3RT2026-1KB40 (same coil voltage, different terminal type — screw terminals instead of spring-type). The 3RT2026-2BB40-ZW96 and -2BB44-ZX95 variants use different coil voltages or special versions.