Product Description:

The FC-301P37KT2131B8979 is a variable frequency drive produced by Danfoss for the VLT FC 301 Automation Drives series. By rectifying and then modulating three-phase mains power, the unit allows PLCs to adjust induction motor speed without mechanical throttling, which is common in pump, fan, and conveyor applications. Its control terminals provide both analog and digital interfaces, so process signals can command setpoints while status bits report alarms and operating states to higher-level controllers.

The drive delivers a continuous output of 37 kW, equivalent to 50 HP, giving it sufficient capacity for medium-sized production machinery. It connects to a 200–240 VAC three-phase line and tolerates supply deviations of ±10% without derating. Internal PWM circuitry reproduces motor voltages from 0–100% of the input level, and the output frequency can be set between 0–590 Hz, enabling low-speed torque and operation above synchronous speed. Analog feedback is available through a 0/4–20 mA transmitter, while two digital outputs source up to 40 mA for relays or optoisolators. Four digital inputs accept 0–24 VDC control signals, and an overvoltage alarm is triggered when the DC link reaches 410 V. The product has an IE2 energy-efficiency classification, indicating modest conversion losses during full-load operation.

For installation, the inverter supplies full current at ambient temperatures up to 45 °C and can be mounted at elevations up to 1000 m without altitude compensation. Motor leads may be routed through up to 50 m of shielded cable or 75 m of unshielded cable, allowing the cabinet to be placed away from the driven equipment. Displacement correction inside the unit provides a true power factor of ≥0.9, helping reduce reactive current in the upstream supply conductors. When the mains frequency varies by ±5% around 50 or 60 Hz, the control maintains stable motor flux and consistent process speed across different power systems.