SIRIUS S0 power contactor — 34 A at 480 V, current lifecycle
The Siemens 3RT2028-1AP00-ZX95 is a SIRIUS power contactor in the S0 frame size, rated 34 A for AC-3 motor switching at 480 V. That rating governs its real-world motor load capacity — it handles a 5 hp motor at 230 V and pulls the full 34 A at 480 V, so it's sized for a 15–20 hp motor on a 480 V line. It mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 60715, and the mounting position allows ±180° rotation on a vertical surface plus ±22.5° tilt forward/backward — useful for tight panel layouts.
The contactor occupies a 45 mm wide DIN-rail footprint with a depth of 97 mm and height of 85 mm. Solid or stranded conductors from 1 to 10 mm² are accepted on the main terminals; the auxiliary contact wiring accepts 2x (0.5 to 1.5 mm²) or 2x (0.75 to 2.5 mm²). The S0 frame is the standard size for this current class — it fits alongside other S0 devices on the same rail without crowding.
Rated for 1 000 000 operating cycles typical. Maximum switching frequency varies by duty: 1 000 cycles/hour at AC-1 (resistive), 750 cycles/hour at AC-2 and AC-3 (motor starting/running), 250 cycles/hour at AC-4 (plugging/inching). Arcing time is 10 ms. The auxiliary contact carries 10 A at 24 V DC, 2 A at 48/60 V DC, 1 A at 110 V DC, 0.9 A at 125 V DC, 0.3 A at 220 V DC, and 3 A at 400 V DC — so it handles DC control circuits up to 400 V but derates significantly above 24 V.