Current ratings and thermal derating profile
The 3RW4426-3BC44: This derating curve sets the real-world continuous current capacity inside a warm panel — the 133 A figure applies only at the 40 °C reference point, and the actual motor FLA must fall within the derated value at the enclosure's internal ambient. The insulation voltage rating of 690 V provides headroom above the 230 V operating level, while the operating frequency range of 50 to 60 Hz covers global line supplies without derating.
Integrated bypass and adjustable current limit
An integrated bypass contact system switches the thyristors out of the circuit once the motor reaches full speed, eliminating SCR conduction losses during continuous run. This directly reduces heat dissipation inside the panel and improves overall system efficiency compared to soft starters that keep the thyristors in circuit. Adjustable current limitation allows tuning the starting current peak between the minimum load threshold of 8% and the full rated current. For applications with light initial loads or conveyors that must not jolt, this parameter sets the acceleration torque profile.
Mounting envelope and panel integration
The 3RW4426-3BC44 measures 170 mm wide by 192 mm high by 270 mm deep, with screw-fixing mounting. Minimum clearance requirements are 100 mm upward, 75 mm downward, and 5 mm at the sides for airflow and cable bending radius. The mounting position allows vertical surface orientation with ±90° rotation and ±22.5° tilt front-to-back, giving flexibility in tight panel layouts while maintaining the derating and cooling assumptions.
Wiring terminals and cable sizing
Main current circuit connections use box terminals accepting stranded cable sizes 2x (4 to 50 mm²) or AWG 10 to 1/0 using both clamping points. The back and front clamping points each accept AWG 10 to 2/0, providing options for parallel feeds or larger single conductors. Auxiliary and control circuits terminate via spring-loaded terminals accepting solid wire 2x (0.25 to 1.5 mm²) or AWG 24 to 16. Maximum motor cable length is 500 m, which governs installation in distributed motor centres where the soft starter is remote from the load.
Environmental and protection features
Operating temperature range is up to 60 °C during operation, with storage from -25 to +80 °C. Built-in motor overload protection and intrinsic device protection are standard, with an external reset input and a display for fault signal indication. The inside-delta circuit configuration is supported for motors wired in delta during start.