Product Description:

The 175G5301 soft starter is manufactured by Danfoss within the MCD Soft Starters series. It is intended for fixed-speed, three-phase induction motors where controlled ramp-up and ramp-down reduce mechanical stress and line disturbances. By limiting starting current, the device protects gearboxes, belts, and upstream switchgear in automated lines. The design slots into low-voltage control cabinets used across conveyors, HVAC blowers, and pump stations, providing a compact electronic alternative to traditional electromechanical starters and star-delta arrangements in industrial automation environments.

The control section accepts a wide supply range of 110/240 VAC or 440 VAC, allowing the same model to be energized from standard auxiliaries in either low- or high-voltage plants. During runtime, the logic circuit draws up to 100 mA, but the start sequence can momentarily demand 10 A of inrush, so auxiliary fusing must be sized accordingly. The module occupies only 30 mm of DIN-rail width and corresponds to the compact A-Frame mechanical format, easing retrofit in crowded panels. It receives three-phase mains between 200 and 440 VAC and can start motors rated at 30 kW. An IP20 housing limits finger access yet allows free convection, while its Class B EMC classification keeps conducted and radiated emissions within typical plant limits.

For repetitive tasks, the unit is thermally characterized by a heavy-duty profile of 49 A: AC53b 4-20:340, whereas the normal-duty setting supports 60 A with a 4-6 duty cycle. In the event of upstream faults, it withstands a prospective short-circuit current of 5 kA, and the thyristor assembly carries an I²t value of 18 000 A²s. Heat generated during acceleration is predictable at 3 W/A, simplifying enclosure ventilation calculations. Mechanical contacts are avoided, giving an operational life of 1 000 000 operations under rated conditions.