Variable frequency drives (VFDs), also known as variable speed drives (VSDs), are used to modulate the speed of motors in various applications, from hydronic water pumping to VAV fan units to vacuum systems.

While both belt and direct drive fans have been around for a long time, the mainstay fan for most industrial fan applications under 250 hp has been the belt drive fan.

Today’s data centers handle an increasing volume of global digital communication traffic compared to their predecessors of yesteryear. The computers and digital devices that provide streaming video, Internet of Things (IoT) data, business communications, etc. are driving the growth of new data centers to handle this traffic.

Since as early as the 1990s, there have been questions, discussions, and application notes on the topic of using a 2-contactor bypass or 3-contactor bypass with variable frequency drive (VFD) configurations.

Variable frequency drives (VFDs) save energy, increase the life of mechanical systems, and offer valuable control features in a wide range of building management applications.

Baylor University, a private college in Waco, TX, had a typical chiller plant — it ran well, but it was also a hodgepodge of equipment.

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