Product Description:

The 175G5240 is a solid-state motor starter produced by Danfoss and supplied in the MCD Soft Starters series. Installed ahead of induction motors, it raises line voltage gradually during start and lowers it on stop, which limits mechanical shock and peak current on connected equipment. Thyristor phase control in place of direct-on-line switching prolongs coupling life, curbs belt slippage, and helps prevent nuisance trips of upstream breakers when large drives are brought online. Softer pump priming and quieter fan run-ups are additional benefits in HVAC and materials-handling equipment.

The starter’s logic and trigger circuitry operate from a control supply of 110/240 VAC or 440 VAC, so the control section can be powered from either an auxiliary low-voltage source or a higher utility phase. Its power section tolerates network potentials from 200-575 VAC, covering common 208 V, 400 V, and 480 V plants with one catalog code. With a motor rating of 90 kW, it meets the demand of mid-frame motors found on compressors and loaded conveyors. The normal-duty profile is 170 A: AC53b 4-6:594, which corresponds to a 4 s ramp-up, 6 s ramp-down, and a minimum 594 s off time that keeps internal silicon temperature within design limits. Built exclusively for three-phase power, the unit synchronizes firing angles on two phases while the third phase tracks the controlled line, ensuring balanced current and symmetric torque during acceleration.

The physical design uses the C-Frame footprint, matching 200 mm switchboard bays and leaving clearance for cable terminations in standard panel layouts. At 6.8 kg, the unit remains manageable during panel mounting and cable connection in enclosed cabinets. Control and protection functions coded as series 202 provide a fixed ramp law, over-temperature cutout, and a programmable restart block used on medium-duty cycles. It is part of the VLT Soft Starter MCD product group.