What the ATEX and IECEx ratings mean for your hazardous-area motor circuit
The 3RW5055-2TB05: This soft starter carries both ATEX and IECEx certification, meaning it is approved for installation in explosive atmospheres per the ATEX directive and the IECEx scheme — a requirement for motor starting in Zone 1 or Zone 2 gas environments or Zone 21/22 dust areas, depending on the full system certification. The trip class is preset to CLASS 10A / 10E, with a selectable CLASS 20E option per IEC 60947-4-2. CLASS 10A clears an overload in under 10 seconds at 7.2× Ie — fast enough to protect a standard motor winding during a stall without nuisance tripping on a normal start. Rated voltage covers 200 to 600 V, so it handles common low-voltage motor supplies from 208 V through 480 V and up to 600 V without a separate voltage tap.
Panel integration and mounting constraints
Mounting is by screw fixing — no DIN-rail clip. The unit measures 249 mm deep by 120 mm wide by 198 mm high, so plan for a backplate footprint that accommodates the depth plus the required clearance: 100 mm upwards, 10 mm forwards, 0 mm backwards, 75 mm downwards, and 5 mm at the side.
Fieldbus and control options for networked motor control
The soft starter supports PROFIBUS, Modbus RTU, Modbus TCP, EtherNet/IP, and PROFINET with PROFIenergy — covering the major industrial Ethernet and fieldbus protocols for integration into a PLC-based motor control center. Starting profiles include soft torque, voltage ramp, and pump ramp down — the pump ramp down feature is specifically for reducing water hammer on pump stop, a common requirement in water/wastewater applications. Remote reset is available by cycling the 24 V DC control supply, and auto-reset is configurable — useful for unattended installations where a manual reset after a fault is not practical.
Approvals include UL, CSA, and CE marking, so the part is accepted in North American and European regulatory jurisdictions without additional certification work.