178B0797 by Danfoss

The 178B0797 is an AC variable-frequency drive manufactured by Danfoss and supplied within the VLT 6000 HVAC Drives series. It is intended to modulate fan, pump, or compressor speed so that air-handling and hydronic systems match real-time thermal demand in building automation. Its control behavior suits variable-torque applications in ventilation and water-circulation equipment, where stable speed adjustment supports efficient operation throughout changing load conditions.

This drive operates from a three-phase input of 380-460 VAC, allowing connection to common low-voltage distribution in commercial facilities. Its output section is rated at 45 kW / 60 HP, giving enough shaft power for mid-sized supply fans or condenser pumps without an external step-up transformer. The housing uses a compact IP 54 enclosure, so the electronics remain protected against limited dust ingress and splashing water when wall-mounted in mechanical rooms. Communication with supervisory controllers is handled through Profibus DP V1, which allows setpoint changes and alarm reporting over building management networks. Conducted emissions are reduced by an integrated Class A1/B filter, helping limit high-frequency noise on the mains. The unit ships without factory-installed application options, which leaves expansion slots open for later system changes.

Designed specifically for HVAC duty cycles, the inverter includes an operator interface with LCP, providing local start, stop, and parameter access from the front of the drive. It is supplied as a standard unit, so the base feature set includes functions such as PID regulation, sleep mode, and automatic energy optimization. The power section is without conformal coating, so it is better suited to clean indoor electrical spaces than to corrosive or high-humidity areas. This arrangement supports variable-torque load control in building services where steady airflow and water flow are required.