Panel fit and mounting reality
The 3RW5055-6TB04 measures 120 mm wide by 198 mm high by 249 mm deep — that depth includes the heat sink and fieldbus module, so account for it when laying out the gland plate and cable duct. Mounting is screw-fix only, no DIN-rail clip; the vertical mounting surface can rotate ±90° or tilt ±22.5° front-to-back, which helps when you're shoehorning it into a crowded MCC bucket. Clearance requirements: 100 mm above, 75 mm below, 10 mm in front, 5 mm to the side, and zero at the back. That 100 mm upward gap is non-negotiable for heat dissipation — the unit derates above 40 °C ambient, and stacking cabinets without that headroom will trip you into the derating curve faster than expected.
Motor protection and trip class options
Minimum load is 15% of the smallest settable Ie, and the minimum operating current is 68 A. That 68 A floor means this unit won't regulate a motor drawing less than that — if your BOM has a 30 A FLC motor, step down to a smaller frame.
Fieldbus and control wiring
Built-in fieldbus support covers PROFIBUS, Modbus RTU, Modbus TCP, EtherNet/IP, and PROFINET standard — no add-on module required for any of those. PROFIenergy is available when paired with the PROFINET communication module, which lets the drive park the motor during production pauses and save panel cooling load. Auto-reset and remote reset (by cycling the control supply voltage) are both supported. That remote reset is useful when the starter is inside a locked MCC and the operator station is 50 m away — no need to walk over and push a button.
Hazardous-area approvals and compliance
ATEX, UKEX, and IECEx approvals are all listed — this unit is certified for use in explosive atmospheres. That's a hard requirement for chemical, oil and gas, or grain-handling lines where a standard soft starter would fail the safety case. The ATEX marking means the starter itself won't become an ignition source in a Zone 1 or Zone 2 gas group environment. The UL listing is essential for any panel destined for a US or Canadian site — without it, the local inspector flags the whole cabinet.
If you're replacing an older 3RW5 series unit, confirm the control voltage and fieldbus revision match your existing cabinet wiring before committing.