ABSTRACT
Fans are built to withstand the increased stress of centrifugal force caused by increases in fan speed to a certain limit designated by the fan class. If the fan speed is to be increased, be sure to use the fan laws to calculate not only the needed adjustment to the sheaves and belts but also for the new, required brake horsepower. After the size of the sheave is calculated, it will be necessary to calculate the new belt length needed for the drive system to determine if the belt(s) will need changing. For proper removing or mounting sheaves on fan and motor shafts or adjustment of variable pitch sheaves, consult the manufacturer’s published data. Before trying to remove sheave from or mount sheave on shaft or adjust pitch diameter of a variable speed sheave, be sure to locate all locking screws.
