748 A at 40 °C — the real continuous rating
The 3RW4447-2BC45: That derating curve is the one that governs panel placement — if your enclosure runs hot, the available current drops. The 690 V insulation voltage (IEC 60947-4-2, pollution degree 3) means it handles industrial environments with conductive dust or condensation without tracking. Operating frequency is 50/60 Hz, same coil rating at both line frequencies — no reconfiguration needed when crossing 50/60 Hz regions.
Inside-delta topology and thyristor bank
This is an inside-delta soft starter with thyristor control. Inside-delta wiring means the thyristors sit inside the motor delta connection rather than in the line — reduces the current through the power semiconductors compared to a standard line-fed starter, which is why this unit can handle 748 A in a single chassis. The thyristor bank handles the ramp-up; once at speed, the motor runs across the line through the bypass contactor (not included). Minimum load is 8% of rated current — important if you're starting a lightly loaded pump or conveyor and the starter needs to detect the motor current for protection.
Mounting and connection flexibility
Mounts with screw fixing, vertical surface, rotatable ±90° and tiltable ±22.5° front/back — gives you options when the panel layout is tight. Dimensions are 298 mm deep, 210 mm wide, 230 mm high. Clearance: 100 mm above, 75 mm below, 5 mm at the sides — the side clearance is minimal, so you can pack units close together horizontally. Main circuit connection: busbar or cable. Accepts stranded 70–240 mm², finely stranded 50–240 mm², and AWG 2/0–500 kcmil. The dual clamping points let you parallel two cables per phase — useful when the cable ampacity requires parallel runs. Maximum motor lead length is 500 m — if your motor is farther than that from the starter, you'll need an output reactor or filter to prevent reflected wave damage to the motor insulation.
Protection and diagnostics onboard
Built-in motor overload protection and intrinsic device protection (monitors the thyristor junction temperature and shuts down before damage). Adjustable current limitation lets you set the starting current ceiling as a percentage of the motor FLA. External reset input for remote fault clearing. Display shows fault codes — no guessing which trip hit first.