131X6117 by Danfoss

The 131X6117 is an AC variable-frequency drive manufactured by Danfoss as part of the FC 111 Flow Drives series. It belongs to the broader VLT Flow Drives product group and is intended to modulate centrifugal pump or fan speed so that liquid or airflow matches process demand in industrial automation. By adjusting motor frequency rather than using throttling valves or dampers, the drive supports energy-efficient operation in water treatment basins, HVAC loops, and other installations that require continuous flow regulation.

This model accepts a three-phase supply in the range of 3 x 380-480 V AC, allowing direct connection to typical low-voltage plant power systems without an isolation transformer. The maximum line draw reaches 8.3 A, while the inverter can sustain an output of 9.0 A under steady load and deliver up to 9.9 A for short overloads, giving headroom for transient pressure spikes. A motor rated at 4 kW can be driven continuously, matching the pump sizes normally found on medium-capacity process skids. Three input phases help maintain balanced torque, and the absence of an internal brake unit indicates that regenerative deceleration is not expected in typical flow applications.

The electronics are housed in an IP20 enclosure with a back plate, so the drive must be mounted inside a ventilated cabinet when airborne dust or moisture is present. Conducted emissions are limited by an integrated EMC filter classified as A1 (C2), which helps support compliance with industrial EMC requirements. A reinforced coating on the control boards adds protection against humidity and chemical vapors, and the design is certified for the T4 voltage class. Because no Local Control Panel is fitted, parameter entry occurs through remote fieldbus or optional plug-in interfaces, which can simplify panel layouts in distributed pump stations.