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.
There’s no one-size-fits-all solution for a cooling tower replacement. This is especially true in urban population centers and atop high-rise buildings.
Facilitating such mechanical upgrades, one must focus on all factors, including identifying critical loads, electrical system sizing, load shedding, and more.
Size and configuration are important, but don’t overlook other key factors that can help provide the best return on investment and total cost of ownership over the life of the system.
Voltage spikes, bearing or winding failure, capacitance/insulation issues... you may have one of these problems to solve (or better, to avoid) in order to enjoy the full benefits of your drive.