Motor protection timing that matters at startup
The 3RU1146-4KD0 is a SIRIUS thermal overload relay in the Size S3 frame, built for motor protection in the 55–65 A range.
Terminal choices that save wiring time
Main power circuit uses screw-type terminals accepting 2x (10…50 mm²) stranded or 1x (10…70 mm²) — covers the heavy wire for motor feeds. Mounts directly onto the contactor — the fastening method is contactor mounting, with the relay rotatable ±135° and tiltable ±45° on a vertical surface, giving you real flexibility when the panel layout is tight.
Coordination and environmental limits
Short-circuit coordination is specified with gG fuses: 160 A for Type 2 coordination (minimal damage), 250 A for Type 1 (device may need replacement but the circuit clears). Surge voltage withstand is 8 kV, so it sits comfortably in standard industrial installation categories. Operates from -20 to +70 °C, stores and transports from -55 to +80 °C, and handles 100 % relative humidity during operation. Shock resistance is 8g / 10 ms — it'll hold up on a vibrating conveyor or compressor skid.
ATEX and IP20 for hazardous-area panels
Carries ATEX certification (DMT 98 ATEX G 001), so it's approved for use in potentially explosive atmospheres when installed per the directive. Power dissipation per pole is 6.3 W — three poles at 18.9 W total. Factor that into your panel thermal budget, especially in a sealed enclosure with multiple relays stacked.