Product Description:

The 136G7351 soft starter is produced by Danfoss as part of the MCD Soft Starters series. It is installed between the mains and the motor to manage voltage ramp-up and ramp-down, reducing mechanical shock and electrical peak currents during start and stop cycles in automated machinery. By controlling the initial torque, the unit helps extend motor life and reduce stress on gearboxes, pumps, and conveyor drives in general industrial automation. This type of control is especially useful where abrupt across-the-line starting could cause belt slip, hydraulic shock, or unnecessary inrush current.

Designed for three-phase power circuits, the device supplies up to 171 A of continuous line current. It uses an internally bypassed arrangement, so after the start sequence, conduction losses shift from the thyristors to integrated contactors. The switching elements are rated for 100000 operations, which supports repeated use in frequent-start applications. Panel enclosure is required because the soft starter has an IP00 protection level. Line disturbances are addressed with an impulse withstand capacity of 6 kV. Mechanical integration follows frame size 2 dimensions, which helps keep mounting and terminal layout consistent within the product line.

Thermal capacity under IEC duty curves is expressed by a 3.0-10 rating of 200 A and a 3.5-15 rating of 170 A, allowing the unit to handle different start durations and cooling intervals. Its insulation system is approved for up to 690 V AC, so it can be used in industrial power systems within that voltage class. For North American installations, the starter also aligns with NEMA heavy-duty 104 A and normal-duty 131 A motor categories. These duty classes help show how the starter behaves under repeated starts and different load conditions, especially when acceleration time and thermal recovery must be balanced. The result is a clearer view of how the unit fits applications that demand controlled motor starting without excessive electrical or mechanical strain.