V-belt Drive Losses: Our published brake horsepowers do not include for V-belt drive losses. Before selecting motor size, an allowance should be made for this drive loss.

Example:

Fan BHP from performance charts = 41 H.P.
Approx. drive loss from chart shown below = 2 H.P.
Approx total horsepower = 41 + 2 = 43 H.P.
Use 50 H.P. motor