The Siemens 3RF3190-3AA44 is a 1-pole SIRIUS 3RF31 solid-state relay in the 22.5 mm wide housing, rated for 90 A continuous load current across a 48-460 V AC supply range. Control is 4-30 V DC, making it compatible with standard 24 V DC PLC outputs without a series resistor. The ring cable lug termination is designed for bolting to an external heatsink — this relay has no internal heatsink and relies on the mounting surface for thermal management.
The ring cable lug connection (not spring-cage or screw-clamp) means you need a bolted bus bar or stud on the heatsink for the load terminals — plan for M5 or M6 hardware depending on lug ring size.
What the 90 A rating means in practice
90 A is the continuous rated current for resistive loads (AC-1 duty class). For motor loads or inductive switching, derate per the SIRIUS application manual — typically 50-60% of the resistive rating. The 48-460 V AC range covers common three-phase line voltages (230 V, 400 V, 480 V) but note this is a single-pole device: for three-phase switching you need three units or a three-pole variant. The 4-30 V DC control threshold means it triggers reliably from 24 V DC logic outputs, even with long cable runs that drop a few volts.