S00 frame — what the 20-12 A rating means for your load
The 3RT2016-2AP04-3MA0: The 20 A ceiling applies in AC-1 resistive duty; the 12 A figure is the AC-3 motor-switching limit — the rating that governs real motor starts and stops. Switching frequency depends on the duty class: AC-1 allows up to 1000 operations per hour, AC-3 and AC-3e cap at 750 ops/h, and AC-4 (plugging/inching) drops to 250 ops/h. For a conveyor running 30 starts per hour, the AC-3 ceiling is irrelevant; for a rapid-reversing application, the AC-4 limit is the binding constraint.
Panel fit — the 121 mm depth is the number that matters
The 3RT2016-2AP04-3MA0 measures 45 mm wide, 70 mm high, and 121 mm deep. The depth is the dimension that catches panel builders — most S00 contactors sit around 100 mm, so this variant needs an extra 21 mm of enclosure depth behind the DIN rail.
Wiring — spring terminals on the coil, screw on the main
The magnet coil uses spring-type terminals — no screwdriver needed, just push in the stripped wire. Arcing time is 10-15 ms at AC, with a make time of 4-15 ms.
The part carries no auxiliary switch block; if your circuit needs an aux contact, order the add-on block separately.