131F1931 Danfoss VLT FC-102 HVAC Drive 11 kW / 15 HP, 380 – 480 VAC, IP21

Danfoss 131F1931 at a glance

The Danfoss 131F1931 is an 11 kW VLT HVAC Drive FC 102 for 3 × 380–480 V AC supplies, made for the fans, pumps and compressors in building services. It is a frame B1, IP21 / UL Type 1 unit, suitable for mounting in clean, dry indoor plant rooms.

This configuration has RFI class A1/B (C1), no brake chopper, a graphical LCP 102 control panel, and a LonWorks MCA 108 fieldbus card. The full type code is decoded alongside the FAQs.

Sizing and installation

• Enclosure: IP21 / UL Type 1 — suitable for mounting in clean, dry indoor plant rooms.
• EMC: RFI class A1/B (C1). Check the permitted screened motor cable length in the Danfoss FC 102 Design Guide.

FC 102 features for HVAC

• Built-in RS-485 protocols: Danfoss FC, Modbus RTU, BACnet MS/TP, Metasys N2 and FLN Apogee — connects to most building management systems without an option card.
• Fire Mode keeps the drive running during an emergency, for example to keep smoke-extract fans turning.
• Automatic Energy Optimisation (AEO) cuts motor losses at part load — Danfoss quotes a further 5–15% saving.
• Pump and fan functions: sleep mode, dry-pump, end-of-curve and broken-belt detection, plus a built-in cascade controller for pump sets.
• Built-in DC coils limit mains harmonics (EN 61000-3-12).
• Smart Logic Controller for simple sequencing without a PLC.

Where the energy saving comes from

Centrifugal fans and pumps follow the affinity laws: absorbed power falls with the cube of speed. Running at 80% speed needs roughly half the power of full speed (0.8³ ≈ 0.51, before motor and drive losses) — which is why speed control pays back faster on fans and pumps than almost any other load.

Other sizes and enclosures

Same 11 kW rating, other enclosures

Typical applications