VLT6005HT4B20STR3DLF00 by Danfoss

The VLT6005HT4B20STR3DLF00 is an AC variable-frequency drive manufactured by Danfoss as part of the VLT 6000 HVAC Drives series. It is intended to modulate induction-motor speed in building ventilation, pumping, and chiller loops so that air-handling or fluid-circulation equipment can track actual load demand rather than running at fixed mains frequency. By integrating motor control, overload protection, and harmonic mitigation in one chassis, the product helps reduce energy consumption and extend mechanical life in centralized or distributed HVAC installations. This type of control is useful in systems that operate under changing demand throughout the day rather than at a constant full-load condition.

The drive accepts a three-phase input of 380-460 VAC, allowing direct connection to common low-voltage distribution boards without an autotransformer. Its output capability is rated at 3.0 kW, or 4.0 HP, matching small supply fans and hydronic pumps used in branch circuits. The book-style IP 20 enclosure suits dense MCC panels where space savings and finger-safe access are both priorities. A front-mounted graphical keypad with an LCP (Local Control Panel) provides parameter entry, local start and stop control, and fault readout without external tools. For conducted-emission compliance, the internal EMC stage includes a Class A1 and B filter to reduce high-frequency noise on the building power bus. Its narrow housing format also helps when multiple drives must be mounted close together inside a control cabinet.

The unit is intended for HVAC load profiles, and its control board is supplied as a standard unit rather than a custom-option build. Fieldbus connectivity is omitted, so control can rely on hard-wired analog signals or the onboard keypad, which supports integration with existing building management inputs. Operating functions typical of this drive type include proportional-integral regulation, sleep mode, and automatic restart for airflow and water-balance applications in commercial climate-control systems. These features support stable control during normal ventilation and pumping duty where demand may rise and fall over time.