FC111P55KT4 Danfoss VLT HVAC Basic Drive 55kW

Product Overview

The FC111P55KT4 (FC111P55KT4) is a dedicated VLT® HVAC Basic Drive engineered by Danfoss to provide optimized performance for large-scale fan, pump, and compressor applications. With a robust shaft output of 55.0 kW (70.0 HP), this frequency converter is designed to streamline HVAC operations in commercial buildings and industrial facilities. The FC111P55KT4 focuses on energy efficiency, achieving an impressive 98.2% typical efficiency rating, which significantly lowers operational costs and reduces the carbon footprint of the facility. Housed in a heavy-duty H7 enclosure with an IP20 protection rating, it offers a compact yet powerful solution for motor speed control, ensuring smooth starts and precise flow regulation to extend the mechanical life of high-capacity HVAC hardware.

Technical Configuration

The VLT® HVAC Basic Drive platform is built for "fit and forget" reliability. This specific 55 kW unit is designed for three-phase mains supply ranging from 380 to 480 VAC. The hardware supports high-current demands, delivering up to 106.0 A of continuous current at 400 V, with an intermittent capacity of 116.0 A for startup torque requirements. The H7 frame size is engineered for superior thermal management, capable of operating at full capacity in ambient temperatures up to 40 deg C, and maintaining significant output even under de-rating conditions at 50 deg C. Its control interface is optimized for HVAC-specific functions, including built-in PID controllers and fire mode, ensuring the system remains a reliable safety asset in critical building automation architectures.

Technical Specifications

Technical FAQs

How does the FC111P55KT4 handle high ambient temperatures?

The drive is rated for full output at 40 deg C. If the environment reaches 50 deg C, the drive automatically implements a de-rating strategy, providing 74.2 A of continuous current at 400 V. This ensures the drive continues to operate and protect the motor without tripping on over-temperature alarms.

What are the primary energy-saving features of this HVAC drive?

The unit features Automatic Energy Optimization (AEO), which dynamically adjusts the output voltage to the motor based on the actual load. Combined with a 98.2% peak efficiency, it significantly reduces power loss—estimated at only 1133 W under typical best-case scenarios for a 55 kW load.

What is the "Fire Mode" and how does it function in this model?

Fire Mode is a safety feature that, when activated, overrides the drive's internal self-protection deratings and alarms. This ensures the fan continues to run to clear smoke or provide pressurization during an emergency, prioritizing building safety over the drive's electronics.

Engineering & Installation Guide

• Terminal Management: The H7 frame supports cable sizes up to 50 mm2 (1 AWG). Ensure that high-quality copper conductors are used and that the terminal screws are tightened to the manufacturer-specified torque to prevent localized heating at the connection points, especially given the 106 A continuous load.

• Harmonic Compliance: While the FC111 series is designed for HVAC efficiency, installing a 55 kW drive can impact the power quality of the building transformer. It is recommended to verify the Total Harmonic Distortion (THD) and ensure the drive is integrated with appropriate DC chokes or mains filters if multiple units are running on a single branch circuit.

• Cooling Clearance: Due to the 36 kg mass and the heat dissipation requirements (approx. 1.1 kW), provide at least 200 mm of vertical clearance above and below the H7 enclosure. Ensure the control cabinet has adequate forced-air ventilation to maintain the ambient temperature below the 40 deg C threshold for maximum performance.