Product Description:

The 131B4976 is an AC variable frequency drive produced by Danfoss within the VLT FC 102 HVAC Drives series. It modulates the speed of induction motors that power air handlers, pumps, and cooling towers in commercial and light-industrial HVAC installations. The drive can integrate with building automation systems to regulate airflow, pressure, and water circulation according to operating demand. By varying the motor output frequency instead of relying solely on mechanical throttling, it can reduce unnecessary electrical consumption and limit mechanical stress on connected equipment. Its dedicated HVAC control profile supports use in chilled-water plants and other centralized climate-control systems.

The drive accepts an input supply of 380–480 VAC from a three-phase power supply. It converts the incoming power into a variable-frequency motor output with a continuous rating of 18.5 kW, corresponding to 25 HP of motor capacity. This output range is suitable for medium-sized fans, centrifugal pumps, and cooling-tower motors that require adjustable speed control. The enclosure has an IP21 / Type 1 rating for indoor installation, providing protection against accidental contact and vertically dripping water when installed as required. It is intended for protected electrical rooms or suitable cabinets rather than exposed outdoor locations. The drive regulates motor speed electronically, allowing connected HVAC equipment to respond smoothly to changing load conditions.

The control section includes a graphical local control panel for parameter entry, operating-data views, and fault resets. The panel uses the Standard Language Pack, and the drive is supplied with the standard software release for its configuration. Adaptation A uses standard cable entries to provide conventional routing for incoming power, motor, and control wiring. Adaptation B is omitted, leaving the base arrangement available for compatible installation accessories when needed. The power stack supports dry-room mounting with B, C, D, and E frames, making the assembly suitable for protected indoor operating areas. An integrated RFI filter helps reduce conducted electrical interference that could otherwise affect nearby controls or communication equipment. The selected Brake-Safe Stop configuration does not include a brake chopper, so applications that require dynamic braking must use an appropriate external arrangement. The printed circuit boards are uncoated and should therefore remain protected from condensation, corrosive vapors, and excessive airborne contamination. Standard cable entries and the indoor enclosure arrangement support orderly separation of power conductors from low-voltage control wiring.