VFDs are employed to control the speed of an AC motor for the purposes of enhancing process control, generating energy efficiency and reducing energy consumption. In return, they optimize the operation of various applications that largely rely on electric motors. The drive can also be applied to convert energy from natural or renewable resources such as wind, tides, or sun to be used for local consumption. For instance, energy consumption in centrifugal fan and pump applications works as dictated by affinity laws, meaning when an application requires an 80% flow, the fan will operate at 80% of rated speed and 50% of rated power. Simply put, the speed can be reduced by 20% while requiring only 50% of the power.
Moreover, this fan equipment utilized for fume extraction typically has no speed control. Once the flow is being controlled without regulating the motor speed, it runs at full speed. In many instances, weld fume control systems usually don’t require maximum flow. So a system that runs without controlling the speed wastes a considerable amount of energy and thus, money. In addition to speed control, AC drive also provides a soft startup for the AC motor that reduces mechanical stress and voltage sags, requiring less maintenance while optimizing the life of the equipment. Overall, electrical energy consumption can be reduced by as much as 10%.