178B2003 by Danfoss

The 178B2003 is an AC variable-frequency drive manufactured by Danfoss as part of the VLT 6000 HVAC Drives series. It is intended for motor speed regulation in ventilation and chiller plants, allowing building management systems to match fan or pump output to actual load and reduce energy consumption and acoustic noise in large commercial facilities. This application focus makes the unit well suited for variable-torque service in air-handling systems and chilled-water loops that operate for long periods under changing demand.

This model accepts a three-phase input of 380-460 VAC and delivers up to 1.1 kW / 1.5 HP to the connected induction motor. The slim Bookstyle IP20 housing mounts inside electrical panels where basic finger-safe protection is sufficient and cabinet space is limited. A built-in Class A1 and B filter attenuates conducted radio-frequency emissions so the drive can share switchgear with sensitive HVAC sensors without requiring an additional line filter. The power section is assembled without a coating, which is suitable for clean mechanical rooms where airborne contaminants are minimal.

The unit is supplied without an LCP, so parameter entry is handled through a remote keypad or an external controller. It is also delivered without a fieldbus option, which suits installations that rely on hard-wired analog signals rather than digital network communication. The drive uses a standard unit hardware platform. Its control algorithms are tuned for HVAC duty profiles, so acceleration ramps, fault responses, and carrier frequencies are arranged for fans and pumps rather than high-torque industrial machinery. This layout supports straightforward integration in systems where compact panel installation, electromagnetic compatibility, and simple control wiring are the main requirements.