Motor Protection Circuit Breaker for 16 A Lines
The Siemens SIRIUS 3RV1031-4AB10-ZW96 is a motor protection circuit breaker rated for 16 A continuous current with a Class 20 trip characteristic, sized for a 7.5 kW motor at 400 V AC three-phase. It delivers 50 kA breaking capacity at 400 V AC, dropping to 12 kA at 500 V and 5 kA at 690 V — sufficient headroom for most industrial distribution panels where the fault current at the motor branch is coordinated downstream of a feeder breaker.
The 16 A continuous rating and Class 20 trip curve mean this breaker is set up for standard squirrel-cage induction motors that draw 6–8× FLA during start and need up to 20 seconds to accelerate — typical for pumps, fans, and compressors on a conveyor or HVAC line. The phase failure detection is a hard requirement in IEC 60947-4-1 motor protection: if one phase drops, the breaker trips before single-phasing cooks the winding. Power dissipation runs 14.5 W hot at rated current, or 4.8 W per pole. In a densely packed enclosure with multiple breakers side by side, that heat adds up — account for derating if ambient inside the panel exceeds 40 °C.
The 55 mm width means it occupies three standard 18 mm module spaces — plan the DIN rail length accordingly. Main circuit terminals accept 2× solid conductors 0.75–16 mm² or 2× stranded 0.75–25 mm², with a single larger terminal for 1× 0.75–35 mm² stranded. AWG equivalents are 18–2 for solid, 18–2 for stranded on the main contacts. Screw-type box terminals on the main circuit and screw terminals on the auxiliary/control circuit — torque to the manufacturer's spec during commissioning.
RoHS substance prohibition date is July 1, 2006, indicating compliance with the original RoHS directive.