What the 1351A rating means in your enclosure
The 3RW4456-2BC35: Insulation voltage rated 690 V gives headroom on 400/480/575 V systems, and the 50/60 Hz operating frequency means one unit covers both line frequencies globally.
Inside-delta wiring and bypass — what they save you
Inside-delta circuit capability lets you wire the thyristors inside the motor delta winding, reducing the current the soft starter must handle to 58% of the line-fed rating — a 1351 A line-rated starter covers a motor that would otherwise need a 2300 A unit in line configuration. Integrated bypass contact system means the thyristors are shorted out once the motor is at full speed — no external bypass contactor to buy, wire, or lose space for, and the heat load in the panel drops to the bypass contact resistance instead of the thyristor forward voltage drop.
Mounting, clearances, and wiring — what fits in the panel
Clearance requirements: 100 mm above for cable entry and airflow, 75 mm below, and only 5 mm at the sides — the side clearance is tight enough that adjacent units can be mounted side-by-side without a gap, but the vertical space is mandatory for the busbar connections and natural convection. Main circuit wiring accepts stranded 70-240 mm² or finely stranded 50-240 mm², or busbar connection — the busbar option is the cleanest for the 1351 A range, avoiding the bending radius and lug stack-up of parallel cables. Auxiliary and control circuit terminals are spring-loaded, accepting solid 0.25-1.5 mm² — tool-less insertion for PLC and relay signals, and the spring clamp holds under vibration better than screw terminals.
Protection layers and diagnostics
Motor overload protection, intrinsic device protection, and adjustable current limitation are all built in — the soft starter can replace a separate overload relay for most applications, and the current limit setting lets you cap inrush to protect driven machinery. Pollution degree 3 per IEC 60947-4-2 certifies the unit for industrial environments with conductive dust or occasional condensation — the creepage distances and enclosure sealing are designed for that severity level. A display for fault signals gives local diagnostic readout without a separate HMI or laptop — the first thing a technician looks at when the starter trips on a phase imbalance or over-temperature event. Motor brake output integrated means a brake motor can be controlled directly from the soft starter without a separate brake contactor — saves a panel component and the wiring between them.