How do I adjust a pulley?
There is an adjustable sheave on the motor. There are two hex set screws on the pulley. One secures the pulley to the shaft. The other allows the two halves of the pulley to be adjusted closer together or further apart. Be sure when adjusting to retighten the set screws on a flat side of the pulley base. Adjusting the halves closer together increases the fan speed, further apart slows it down. Double grove pulleys must be turned the same number of turns or the belts will not seat properly in the groves. Always check motor amperage after adjusting pulleys.