Soft starter for ATEX/IECEx zones — trip class and fieldbus fit
The Siemens 3RW5073-2TB04 is a soft starter rated for a minimum motor current of 100 A and an operating voltage range of 200-480 V. It ships with a preset trip class of CLASS 10A / 10E (preset) / 20E per IEC 60947-4-2, which defines the overload protection curve for starting heavy loads like conveyors or pumps without nuisance tripping. ATEX and IECEx certification (both listed) means this unit is approved for installation in explosive atmospheres — a mandatory requirement for chemical, oil & gas, or grain-handling lines where motor starting equipment sits in a classified zone. The approvals cover the enclosure and internal isolation, not just the external terminals. Fieldbus support is comprehensive: PROFIBUS, PROFINET (with PROFIenergy), Modbus RTU, Modbus TCP, and EtherNet/IP are all on the order code. This lets the starter integrate into a Siemens S7 or third-party PLC without an external gateway — the drive parameters, start/stop, and fault log are available over the network.
Mounting, derating, and environmental limits
The unit measures 282 mm deep, 160 mm wide, and 230 mm high, with screw fixing to the back panel. Mounting position allows vertical surface with ±90° rotation and ±22.5° tilt forward/back — useful when the panel layout forces a non-flat orientation. For a panel with multiple drives stacked, the internal ambient rise may push past 40 °C — the derating curve must be applied to maintain full rated current. Shock resistance is 15 g / 11 ms, with potential contact lifting above 12 g / 11 ms. This is relevant for mobile equipment or installations near vibrating machinery; the mounting bracket and cable strain relief should be rated for the same level.
Sourced through independent distribution against an RFQ. The unit carries UL, CSA, and CE approvals, which covers North American and European compliance documentation for the BOM.