178B4878 by Danfoss

The Danfoss 178B4878 converter is a variable-frequency drive in the VLT 5000 Frequency Converters series. Designed for plant-wide automation, it modulates the output frequency sent to induction motors so that speed and torque follow process demands with minimal energy loss. By translating fixed mains power into controlled three-phase output, the unit serves in conveyors, mixers, and pump skids that need accurate ramping, controlled braking, and continuous-duty regulation. This operating method lets connected equipment run at process-appropriate speeds instead of remaining at a fixed motor speed during every stage of operation.

The unit accepts a 380-500 V three-phase supply and can remain connected on feeders with fault levels up to 100,000 A. During momentary heavy loading, its high-overload branch delivers 106 A, while the normal 110% profile can sustain 147 A for one minute before returning to nominal output. At 400 V, it produces an apparent output of 102 kVA and supports a constant-torque rating of 75 kW. These output levels suit demanding motor-control tasks that require stable performance during long operating cycles. Power is managed by a process control card that handles vector regulation, and the converter includes a display module for local parameter access.

System integration is simplified by the built-in Profibus DP V0/V1 interface at 12 Mbaud, allowing the process control card to exchange setpoints and status information with PLCs. The enclosure uses a compact IP20 enclosure for installation inside clean electrical panels, and Class A1/B RFI filtering limits conducted emissions on the supply lines. A rated input draw of 128 A and a true power factor of 0.90 help with upstream supply sizing and protection selection. The boards are non-coated, and the converter has no application option installed. The design also calls for a minimum motor cable cross-section of 25 mm² to support stable voltage on long runs, and phase sequencing is fixed for three-phase machines.