Product Description:

The 137H8978 is an AC variable-frequency drive produced by Danfoss within the VLT FC 302 Automation Drives series. The unit regulates induction motor speed in automated machinery and supports closed-loop control of conveyors, pumps, and other general-purpose motion functions in industrial systems. It is intended for automation duties where a single drive must handle changing process demands without mechanical speed changes. A detachable Graphical Local Control Panel provides local access to speed, fault codes, and process variables through a backlit display and navigation keys.

This drive accepts a mains supply of 380 - 500 VAC on a three-phase power network and delivers up to 22 kW of mechanical output, which is equivalent to 30 HP. That output range suits medium-size motors used in production equipment where controlled acceleration and steady running speed are required. The IP20 chassis enclosure allows installation in ventilated control cabinets while helping prevent finger contact with live parts. Standard cable entries, normal cabinet mounting for A, B, and C frames, and an uncoated printed circuit board support straightforward cabinet integration in common industrial enclosures.

An internal RFI Class A1/B (C1) filter suppresses conducted emissions so the drive can share switchboards with sensitive PLC hardware and other nearby control electronics. An integrated brake chopper dissipates regenerated energy during emergency stopping or high-inertia deceleration, which can help reduce stopping time and improve deceleration control. For position-feedback applications, the optional MCB-103 Resolver Option fits the B-option slot and supplies analog rotor angle data to the drive for vector-mode torque regulation without an encoder. This arrangement supports resolver-based feedback when an application requires rotor position information rather than standard open-loop speed control.