Panel Fit and Mounting Constraints
The 3RT2028-1AP04-ZX95 is a size S0 power contactor with a width of 45 mm and a depth of 141 mm — the depth is the dimension that dictates enclosure selection, especially in shallow backpanels or retrofit cabinets where gland-plate clearance is tight. Mounting is via screw or snap-on onto 35 mm DIN rail per DIN EN 60715, with the mounting position allowing +/-180° rotation on a vertical surface and +/-22.5° tilt forward/backward, so it can be oriented to fit cable entry paths without violating the clearance zones. Minimum air and creepage clearances are specified: 10 mm upwards, 10 mm forwards, 10 mm downwards, and 6 mm at the side — these must be maintained to the enclosure wall or adjacent components to avoid arc flash or tracking under fault.
Rated Motor Current and Duty Cycles
Rated at 34 A at 480 V in AC-3 duty (the standard motor-switching category for squirrel-cage motors), this contactor handles typical North American 480 V three-phase motor loads up to that current — which corresponds to roughly a 20–25 hp motor depending on full-load amps. Maximum switching frequency varies by duty: 1000 operations per hour in AC-1 (resistive), 750/h in AC-2 and AC-3, and 250/h in AC-4 (plugging/inching) — so for high-cycle applications like conveyor indexing or compressor cycling, stay within the AC-3 ceiling of 750 ops/h to avoid contact wear. The contactor's mechanical life is rated at 10 million operations typical, with an arcing time of 10 ms at 50 Hz — this is the contact separation interval during which the arc extinguishes; the 4–16 ms AC arcing window covers variations in load power factor and supply voltage.
Wire Termination and Auxiliary Contact Provisions
Main contact terminations accept solid or stranded wire from 1 to 10 mm² (roughly 18 to 8 AWG), and the magnet coil uses screw-type terminals — no special crimp tooling is required for field wiring, but torque settings should follow the Siemens installation instructions to avoid terminal damage. Auxiliary switch blocks are not included as standard (the base contactor has no auxiliary contacts), so if the application requires feedback or interlocking, a separate auxiliary contact block must be ordered and snapped onto the contactor's side or front — the S0 frame supports Siemens auxiliary switch modules.