The Siemens 3RF3320-1AA02-0KN0 is a 1-pole SIRIUS 3RF33 solid-state contactor rated for 20 A in AC-1 duty at 40 °C. AC-1 is the resistive load category per IEC 60947-4-2 — meaning this rating covers heaters, lighting banks, and transformer primaries where inrush is minimal. For motor or inductive loads, you derate to the AC-3 curve; the 20 A AC-1 figure is the headline for resistive switching. The control circuit accepts 24-230 V UC (universal voltage, AC or DC) and the LP (low power) screw terminal variant draws minimal coil-side current — useful when the PLC output card or control transformer is already loaded. The 24 V DC rail is within range, so no separate supply is needed for the coil. The 27 mm width leaves room for adjacent contactors or auxiliaries in a dense panel layout.
RoHS compliance is confirmed effective 15 January 2024. No additional SVHC candidate substances are flagged beyond that.
As a solid-state contactor, the 3RF3320-1AA02-0KN0 replaces a mechanical contactor in applications requiring silent switching, high cycling rates, or no contact bounce. The 1-pole configuration switches one line in a single-phase circuit or one phase in a three-phase resistive bank. The LP screw terminals accept standard ring or fork lugs; torque to the value printed on the housing. Group code R711 and product group 3725 are Siemens internal cataloging fields that help cross-reference this part in their SIRIUS configurator and spares portal.