Hazardous-area motor starting with ATEX certification
The 3RW5073-2TB05 is a Siemens soft starter carrying ATEX and IECEx certification, meaning it is approved for installation in explosive atmospheres where gas or dust hazards are present. This is the primary differentiator from standard soft starters — the ATEX marking and IECEx marking allow direct integration into Zone 1/21 or Zone 2/22 motor control circuits without additional enclosure isolation. Rated for a minimum operating current of 100 A with a control supply voltage range of 200–600 V, this unit covers global line voltages from 208 V to 600 V without a transformer tap change. The wide input window simplifies BOM planning for multi-voltage sites.
Trip class and overload protection for motor heating
The trip class is configurable as CLASS 10A, 10E, or 20E per IEC 60947-4-2. The preset is 10E, which matches most pump and fan applications. The minimum load setting is 15 % of the smallest settable Ie, which means the starter can be tuned down to protect lightly loaded motors without nuisance tripping. This is relevant when the motor FLA is near the lower end of the 100 A minimum.
Fieldbus integration and communication options
The 3RW5073-2TB05 supports PROFIBUS, Modbus RTU, Modbus TCP, EtherNet/IP, and PROFINET with PROFIenergy. This multi-protocol capability means the same hardware can be commissioned on a Rockwell ControlLogix network (EtherNet/IP) or a Siemens S7-1500 (PROFINET) without a gateway. The PROFIenergy profile allows the starter to pause loads during production breaks, saving energy at the panel level. Remote reset is achieved by cycling the 24 V DC control supply off and on. The error logbook is available only with special accessories — if fault logging is required for your maintenance plan, factor in the additional module at the BOM stage.
Mounting dimensions and panel integration
The unit measures 160 mm wide × 230 mm high × 282 mm deep and is fastened via screw fixing. The mounting position allows vertical surface mounting with ±90° rotation and ±22.5° tilt forward/backward — this gives flexibility in tight enclosures but requires the derating curve to be checked if the unit is not vertically oriented. Clearance requirements: 100 mm upwards, 10 mm forwards, 0 mm backwards, 75 mm downwards, and 5 mm at the sides. The zero backward clearance means the unit can be mounted flush against the back panel, saving depth in shallow enclosures.
Operating temperature and derating
In a non-air-conditioned panel in a Middle East or Southeast Asian plant, the internal temperature can exceed 50 °C — the derating curve must be applied to the continuous current rating to avoid thermal overload trips during normal running. Shock resistance is rated at 15 g / 11 ms, with potential contact lifting above 12 g / 11 ms. For installations on vibrating machinery (compressors, large conveyors), the mounting bracket should be isolated or the shock spec verified against the machine's vibration profile.
Compliance and approvals for global installations
The 3RW5073-2TB05 carries UL approval, CSA approval, and CE marking. For a panel destined for a US chemical plant with ATEX-rated equipment, this single starter satisfies both NEC and IECEx requirements without a separate enclosure.
Sourcing and lifecycle — active production
For a line-down spare or a new project BOM, this part is sourced through authorized distribution channels and quoted to order against the RFQ quantity.