What the 40 A AC-1 rating means for your BOM
The 3RF3340-1AA24 is a 1-pole SIRIUS 3RF33 solid-state contactor rated AC-1 at 40 A at 40 °C. AC-1 covers resistive or lightly inductive loads — heaters, ovens, incandescent lighting — where inrush is minimal. At 40 A it switches that load continuously without a heatsink derate at 40 °C ambient; push the ambient higher and you derate per the thermal curve. The voltage range spans 48-460 V AC on the power circuit and 110-230 V AC on the control coil, so it fits standard European and North American line voltages without a separate transformer tap. Screw terminals simplify panel wiring — no special crimp tooling, just a screwdriver. The 1-pole configuration switches one line; for a 3-phase resistive bank you need three units or a 3-pole variant. Mounts on a DIN rail, which keeps enclosure layout standard.