Drives

On shop.atti.it, ATTI offers Variable Frequency Drives (VFD) from INVT and Toshiba for controlling the speed of asynchronous motors, brushless servo drives, direct current motor drives, braking resistors, and accessories for VFDs such as keypads, remote panel cables, communication boards (for example PROFINET), and encoder boards. The VFDs are available in single-phase and three-phase power supplies, in various power ratings.

The Variable Frequency Drive (VFD) adjusts the speed of an asynchronous motor by varying frequency and voltage: it is the most economical solution for pumps, fans, conveyors, and machines where speed variation is required. The servo drive controls a brushless servomotor with feedback from an encoder and precisely manages position, speed, and torque: it is used for positioning axes, automatic machines, and high-dynamics repetitive movements. In summary, the Variable Frequency Drive (VFD) controls speed, while the servo drive controls position.

When a motor controlled by a Variable Frequency Drive (VFD) decelerates rapidly or drags a load (for example, while descending or with high inertias), it acts as a generator and returns energy to the Variable Frequency Drive (VFD). The braking resistance dissipates this energy as heat, preventing the internal voltage of the Variable Frequency Drive (VFD) from rising too high and the Variable Frequency Drive (VFD) from triggering an overvoltage alarm. It should be chosen based on the minimum resistance value and power indicated in the Variable Frequency Drive (VFD) manual.