Belt and Pulley Installation
Belt tension is determined by the sound the belts make when the fan is first started. Belts will produce a loud squeal, which
dissipates after the fan is operating at full capacity. If the belt tension is too tight or too loose, lost efficiency and possible
damage can occur. Do not change the pulley pitch diameter to change tension. This will result in a different fan speed than
desired.
1. Loosen motor plate adjustment nuts on L-bolts and move motor plate in order that the belts can easily slip into the
grooves on the pulleys. Never pry, roll, or force the belts over the rim of the pulley.
2. Slide the motor plate back until proper tension is reached. For proper tension a deflection of approximately ¼” per foot
of center distance should be obtained by firmly pressing the belt. Refer to Fig. 7.
3. Lock the motor plate adjustment nuts in place.
4. Ensure pulleys are properly aligned. Refer to Fig. 8
Fig. 7 – Belt & Pulley Tension
Pulley Alignment
Pulley alignment is adjusted by loosening the motor pulley setscrew and by moving the motor pulley on the motor shaft, or by
moving the entire motor along the motor mounting bracket. Fig. 8 illustrates correct and incorrect pulley alignment
.
Fig. 8 – Pulley Alignment
A recommended method of inspecting the pulley alignment is shown in Fig. 9. With the shorter leg of a carpenter’s square or
other straight edge lying along the case of the motor, adjust the position of the motor pulley (or the motor) until the longer leg of
the square is parallel to the belt.
Fig. 9 – Pulley Alignment Method
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