The Siemens 3RB2066-2GF2 is a SIRIUS solid-state overload relay rated for 250 A operational current at 50/60 Hz, with a CLASS 20E trip curve. It mounts directly to a contactor or as a stand-alone unit on the panel, fitting the S10 or S12 frame sizes. The electronic overload release protects motors by monitoring current and tripping after a delay that matches the 20E characteristic — typical for standard-start induction motors driving pumps, fans, or conveyors where the start-up transient lasts up to 20 seconds. The auxiliary contact set is integrated, with a dedicated signaling contact that changes state on trip — the "tripped" message output. Rated switching capacity varies by voltage: 2 A at 24 V, 4 A at 120 V, 3 A at 230 V. The main contact rating holds 250 A continuously across 480 V and 600 V circuits, with a rated insulation voltage of 1 000 V.
Deployment and mounting
Mount in any position — the relay is position-insensitive. Fasten directly to the contactor via the busbar connection for the main circuit, or install it standalone on the panel using the M10 bolts on the main contacts. The enclosure is sized at 120 mm wide, 119 mm high, 155 mm deep. Vibration resistance meets 1–6 Hz at 15 mm amplitude, 6–500 Hz at 20 m/s² for 10 cycles. Shock resistance is 15 g for 11 ms on the main body; the signaling contact in the tripped position withstands 8 g / 11 ms. The auxiliary wiring terminals accept 2x (0.25…1.5 mm²) solid or stranded conductors.