Product Description:

The 175G5243 is a solid-state soft starter manufactured by Danfoss for the MCD Soft Starters series in the 202 variant. It is installed ahead of three-phase motors to limit initial torque and line current, which helps protect gear trains and driven loads during ramp-up and ramp-down. This operating method makes the device suitable for conveyors, pumps, and compressors in automated processing lines where smoother motor starts are required without the abrupt mechanical shock of direct-on-line starting.

The control circuit accepts a supply of 24 VAC/VDC and draws only 2 A of inrush current, so low-power auxiliary transformers or PLC outputs can energize the starter. Main terminals accommodate a line voltage from 200–575 VAC; within that range, an internal bypass thyristor set transfers load current once acceleration is complete, which minimizes heat. Heavy-duty capacity is rated at 30 A AC53b 4-20:340, while the normal-duty rating reaches 34 A AC53b 4-6:354 for shorter starts. A high-frequency trip threshold of 72 Hz helps protect the unit against abnormal supply conditions, and the starter uses frame size A for compact panel layouts. The enclosure has an IP20 rating, so the starter must be mounted inside a cabinet, and conducted emissions meet EMC Class B limits for commercial installations.

The unit has a continuous motor power rating of 15 kW, which aligns it with medium-frame IEC motors used on general-purpose machinery and common process equipment. For applications with frequent starts, the normal-duty rating sets the allowable current and start duration before thermal overload occurs during repeated acceleration cycles. A built-in thermistor cutout set at 2.8 kΩ adds protection by opening the control circuit if the starter overheats, allowing supervisory systems to remove line voltage and prevent device damage before internal temperatures rise too far.