80 A at 40 °C — the rating that decides the motor
The 3RW4046-1BB15 is a SIRIUS S3 soft starter rated 80 A at 40 °C ambient. That 80 A is the continuous current at the device terminals, not the motor nameplate FLA — you size the soft starter so the motor's full-load amps at the actual panel ambient stay below this figure. If the panel runs warm — say 50 °C inside — a 75 A motor is already at the derated limit. The control supply is 110-230 VDC. That is not the common 24 VDC found on many PLC-driven panels; verify the control transformer voltage before wiring. The operating frequency range is 50-60 Hz, so it works on either mains standard without adjustment.
Mounting and clearance — the panel layout constraints
Mounting is screw and snap-on onto DIN rail. The device is 70 mm wide, 170 mm tall, 190 mm deep. Clearance around the unit is specified: 60 mm above, 40 mm below, 30 mm at the sides. Skimp on the top clearance and you choke the convection cooling that supports the 80 A rating. Mounting position is restricted: with the optional fan, the unit can be rotated ±90° on a vertical surface and tilted ±22.5° front/back. Without the fan, rotation and tilt are limited to ±10°. For a retrofit into an existing panel, check that the orientation falls within these limits — mounting it flat on a horizontal surface is not allowed.
Terminal capacity and wiring
That covers most motor feeds up to 80 A without needing a separate terminal block. Auxiliary terminals accept 2x (20-14 AWG). The maximum wire length to the motor is 300 m — beyond that, capacitive charging current from the cable can cause nuisance tripping on the soft starter's internal protection.
Protection and adjustability
Built-in motor overload protection is standard, so you can skip an external overload relay in many installations. Adjustable current limitation lets you set the starting current between 20% and 100% of the device rating — useful for limiting mechanical shock on the driven load. The minimum load is 20% of the rated current; below that the soft starter may not detect the motor correctly. Pollution degree 3 per IEC 60947-4-2 means it is rated for industrial environments with conductive dust or occasional condensation — typical for a motor control center in a factory.