Inverter (VFD) Electrical Panel

An inverter (frequency converter, VFD) is a device that adjusts the motor speed to demand by changing the frequency of the voltage supplying the electric motor. Ventilation fans are often selected with a higher capacity than needed and run throttled with dampers; in this case the motor consumes more energy than necessary. With an inverter electrical panel, the fan can be run at a lower speed that matches the actual demand.

According to the fan laws, the power drawn by a fan changes approximately with the cube of its speed, so even a small reduction in speed can lead to a noticeable reduction in energy consumption. The inverter also provides a soft start for the motor, lowering the starting current and reducing the strain on belts, bearings and mechanical components.

When is it the right choice?

• Systems where the fan is run throttled with a damper
• Production areas where ventilation demand changes during the day
• High-power fan motors that draw a high starting current
• Facilities aiming to improve energy efficiency