Product Description:

The 175G5526 is a solid-state soft starter produced by Danfoss as part of the MCD Soft Starters series. The device is installed ahead of an induction motor to reduce mechanical stress and minimize electrical transients during ramp-up and ramp-down. By controlling the initial voltage applied to each phase, the unit supports conveyor drives, pumps, and fan systems in industrial automation that require smoother acceleration profiles.

In normal in-line wiring, the starter carries 37 A under the AC-53b duty cycle of 3-30:330, while an inside-delta topology raises the permissible motor current to 56 A on the same duty cycle. The starter is designed for three-phase networks, and its main circuit components are insulated for up to 690 V AC, allowing connection to a broad range of supply voltages below that limit. Fault clearance coordination is supported by a high short-circuit rating of 65 kA at 480 V AC and a standard rating of 10 kA at 600 V AC when used with correctly sized protection devices. During each start, the thyristor stack dissipates 4.5 W/A, which is relevant to thermal calculations for control enclosures.

Control and auxiliary functions are powered from a 24 V rail; the starter can sink up to 200 mA on its 24 V output and accepts digital commands at a 24 V DC logic level. The analog input works with sources as low as 600 Ω, enabling process signals to be wired without additional buffering. Status relays are rated for 5 A under AC-15 and 10 A for resistive loads at 250 V AC, while overcurrent protection is provided by a 50 A Class J fuse. The power terminals require a tightening torque of 4 Nm to maintain low contact resistance. The control electronics can withstand 4 kV impulse surges, and the housing carries an IP20 protection rating for installation inside ventilated panels.