250 A solid-state overload relay for motor protection
The Siemens 3RB2066-1GC2 is a SIRIUS solid-state overload relay rated for 250 A operational current at up to 1000 V, 50/60 Hz. The Class 10E trip class means it will trip within 10 seconds at 7.2× rated current — matching the thermal curve of standard AC induction motors during a stall or locked-rotor event. The electronic overload release design provides temperature-compensated protection across the -25 to +60 °C operating range, so the trip curve stays consistent whether the panel is in a cold warehouse or a hot machine room.
Mounting and panel fit
This relay fits the S10/S12 size footprint and mounts directly onto a contactor or as a stand-alone unit on the DIN rail. Dimensions are 120 mm wide × 119 mm high × 155 mm deep — measure the panel depth before committing; the 155 mm projection can be tight in shallow enclosures. Main circuit connections use busbar connection (M10 bolts), while the control and auxiliary wiring accepts 1× (0.5–4 mm²) or 2× (0.5–2.5 mm²) solid or stranded wire. Any mounting position is allowed, so orientation in the panel isn't a constraint.
Auxiliary contact ratings and signaling
The integrated auxiliary switch (signaling contact 97/98) carries the 'tripped' message. Its rated switching capacity varies by voltage: 4 A at 120 V, 3 A at 230 V, 2 A at 24 V, and derated further at higher DC voltages — 0.55 A at 60 V, 0.3 A at 110/125 V, 0.11 A at 220 V. Use the 120 V / 4 A figure for the typical PLC input circuit; the DC ratings matter if you're switching a DC control loop directly.
Environmental and mechanical endurance
Rated for 15g / 11 ms shock (signaling contact 8g / 11 ms in tripped position) and vibration per IEC 60068-2-27: 1–6 Hz at 15 mm amplitude, 6–500 Hz at 20 m/s², 10 cycles. Storage and transport range is -40 to +80 °C — the relay can sit in an unheated warehouse or truck without issue.