Motor protection in a packed panel
The Siemens 3RB2066-1GF2 is a SIRIUS solid-state overload relay rated for 250 A operational current in AC-3e duty at up to 1000 V. It mounts directly on a contactor or stands alone, and the main circuit connects via busbar. The auxiliary switch is integrated and signals the 'tripped' message — no separate add-on block needed for that feedback. Vibration resistance is 1–6 Hz at 15 mm amplitude, then 6–500 Hz at 20 m/s² for 10 cycles — it holds up in a panel next to a big contactor cycling a conveyor.
Wiring and termination
The main contact connection is M10 busbar, torqued down for the full 250 A continuous. Auxiliary contact ratings cover the common control voltages: 2 A at 24 V, 4 A at 120 V, 3 A at 230 V. That 4 A at 120 V gives you headroom to drive a PLC input and an indicator lamp off the same contact. The solid-state design means no bimetal heater to swap — the trip setting is electronic, temperature-compensated from -25 to +60 °C. Storage range is -40 to +80 °C.
Shock, vibration, and environment
Shock resistance is 15g for 11 ms on the main body; the signaling contact in the tripped position is rated 8g for 11 ms per IEC 60068-2-27. That matters if this relay is on a machine with a press or a crusher — the auxiliary contact won't chatter on a bump. The thermal current rating of 250 A holds at both 480 V and 600 V. Substance prohibitance date is 07/01/2006 — this relay meets RoHS and similar material restrictions that took effect around that date.