178B0234 by Danfoss

The 178B0234 is a variable-frequency drive manufactured by Danfoss for the VLT 6000 HVAC Drives series. It is intended to modulate the speed of three-phase induction motors used in air-handling units, pumps, and chillers so that airflow or fluid flow matches real-time demand in building automation systems. By adjusting motor frequency instead of relying on mechanical throttling, the drive reduces energy use, minimizes acoustic emission, and extends the service life of connected equipment.

This model operates from a three-phase input range of 380-460 VAC, allowing installation on common low-voltage distribution networks found in commercial facilities. Its output capability of 2.2 kW or 3.0 HP is matched to small and medium fan wheels or circulating pumps typically found on single air-handling zones. The housing follows a Bookstyle IP 20 format, so it occupies minimal panel width while still protecting internal circuitry from incidental contact. Integrated harmonic suppression is provided by a Class A1 and B filter, which helps the installation meet EMC limits for conducted emissions without additional external components. For supervisory control, the drive includes a Profibus DP V1 interface, enabling parameter access, status monitoring, and alarm reporting directly from a building management system.

A front-mounted LCP simplifies on-site parameter entry, manual start-stop commands, and fault diagnosis without external tools. The electronics are supplied without a coating, so the device is suited to clean electrical rooms where moisture or chemical vapors are not a concern. The drive is supplied as a standard unit. Its configuration is optimized for HVAC duty cycles that feature long periods of partial load, allowing energy savings through proportional speed reduction rather than full-speed operation and bypass damping.