175L1020 by Danfoss

The 175L1020 is a variable speed drive manufactured by Danfoss for the VLT 3000 Variable Speed Drives series. In an automation cabinet, this drive modulates the voltage and frequency supplied to an induction motor so conveyor lines, pumps, or fans can follow process setpoints instead of running at fixed line speed. By adjusting its output in real time, it helps minimize energy use and mechanical stress while remaining compatible with standard three-phase industrial power systems.

The inverter accepts a 440/460/500 V AC three-phase mains input, letting it connect directly to common 480 V utility networks without a step-down transformer. Internal control circuits synchronize with either a 50/60 Hz supply, so the same unit can be installed in regions that follow different grid standards. Its motor section is rated for 2 HP, so any connected load must stay within that continuous shaft power to avoid thermal overload. When a rapid speed change occurs, the drive can deliver an apparent power of 4.7 kVA for up to 60 s, accompanied by a short-term output current of 5.5 A. These overload margins support acceleration torque and short pressure spikes. The largest conductor that fits the output terminals is 12 AWG, and the drive can energize motors up to 3 HP when the duty cycle remains within its cyclic torque limits.

During steady operation, apparent output is limited to 2.9 kVA with a continuous current of 3.4 A. These values affect heat generation inside the enclosure and influence cooling airflow requirements. Full-load conversion efficiency reaches 96 %, so only a small portion of input energy becomes waste heat. A line-side protection device rated at 15 A is recommended to match the drive's inrush and fault-clearing needs without nuisance trips. This helps maintain stable motor torque during extended operation.