Rated current at ambient — the derating curve is the real spec
The 3RW4036-2BB04 is rated 45 A at 40 °C, derating to 42 A at 50 °C and 39 A at 60 °C. That 6 A drop between 40 °C and 60 °C is the number that governs the motor FLA you can hang on it inside a warm panel — the 45 A figure is only valid at the lower ambient. Integrated bypass contact system means the thyristors are shorted out once the motor is up to speed, dropping the heat load in the enclosure and letting the soft starter run at the full rated current longer. Without bypass, the derating would be steeper.
Mounting and clearance — panel fit constraints
Screw and snap-on mounting onto DIN rail; the S2 frame is 55 mm wide, 160 mm high, 170 mm deep. Clearance requirements: 60 mm upwards, 40 mm downwards, 30 mm at the sides — ignore these and the forced-air convection path for the thyristor heatsink is blocked, pushing the junction temperature above the derating curve. Mounting position is restricted: with an additional fan the unit can be rotated ±90° on a vertical surface and tilted ±22.5°; without fan the rotation is limited to ±10° and tilt to ±10°. The orientation matters for the internal thermal design — forced cooling opens the envelope.
Termination and wiring — screw terminals, dual-wire capacity
The front and back clamping points accept 18... 2 AWG and 16... 2 AWG respectively. Maximum wire length to the motor is 300 m — beyond that the voltage drop on start can fool the current-sensing circuit.