132F0002 Variable Frequency Drive Micro Drive FC51 0.4kW 1-ф/220

Danfoss VLT Micro Drive FC 51 — a simple general-purpose VFD up to 22 kW

FC 51 is the entry-level, simplest series in the VLT family. You pick it where you need to smoothly drive an induction motor on a pump, fan or conveyor and have Modbus for SCADA — while complex logic, fieldbus and closed-loop control are not required. In our range these are 0.7 to 22 kW models in three supply versions: single-phase 220 V, three-phase 220 V and three-phase 380 V. Danfoss is a European brand we stock and service; we say honestly where it fits and where a cheaper Veichi makes more sense.

Where FC 51 fits

• Booster and borehole pumps: 0.7–7.5 kW — steady pressure, soft start without water hammer, built-in PID.
• Fans and supply-exhaust ventilation: 1.5–11 kW — energy savings at partial speed.
• Conveyors, mixers, packaging machines: 2.2–22 kW — smooth ramp-up and ramp-down of simple machinery.
• Single-phase sites (farms, workshops, private boreholes): 1×220 V input up to 2.2 kW, three-phase motor on the output.

What sets FC 51 apart

The point is working minimalism from Danfoss. Control in U/f and VVC+ (sensorless voltage-vector mode), support for induction and PM motors, automatic motor adaptation AMA/AMT. Communication is the built-in RS485 interface with FC protocol and Modbus RTU — no add-on card needed. The PCBs are coated, so the drive lives comfortably in a dusty cabinet; side-by-side mounting without derating saves panel space. As a rule the larger frame sizes carry a built-in brake chopper — for dynamic braking you only add a resistor.

The takeaway is simple: if the brand and European service matter and the task is undemanding, FC 51 fits. If budget beats the nameplate, compare it with Veichi AC10.

When FC 51 is NOT the right pick

• You need precise positioning or torque at zero speed with feedback — FC 51 runs only in U/f and VVC+ without an encoder; see servo drives.
• The project mandates Profibus, CANopen or EtherCAT — FC 51 has no expansion-card slots; choose higher VLT lines or another platform.
• You need a full application PLC for complex multi-step processes — FC 51 does have a built-in Smart Logic Controller (parameter group 13: comparators, timers, logic rules) for simple standalone sequences, but it is not a full PLC; for complex process logic choose a drive with an application PLC or an external controller.

Our experience with FC 51

FC 51 is a steady choice for those who deliberately want Danfoss on a simple task. Most often people take the single-phase versions for pumps and workshops and the three-phase 380 V ones for ventilation. The questions are usually the same: is there Modbus (yes, built in), is an EMC filter needed (most versions ship with a built-in RFI filter) and which resistor to use for braking. For plain pump-and-fan jobs we still suggest comparing the price with Veichi — it often saves a noticeable amount without losing reliability.