WaterFurnace Envision (XL) - Manual (Page 37)

ENVISION 7-25 TONS INSTALLATION MANUAL
38
Blower Drive Sheaves
Blower Sheave Adjustment
Follow the procedures listed below if airflow of heat pump is to be changed from factory setting. (Refer to Figure 10.)
1. Loosen the blower motor fastening nuts from the motor mount.
2. Turn the adjusting bolts until the tension is off the drive belt.
3. Remove belt from sheave and loosen allen heat set screw “B”.
4. Adjust sheave pitch diameter for desired speed by opening or closing moveable portion in or out in 1/2-turn increments.
Do not open more than 5 full turns.
5. Sheave should be mounted with set screw “A” toward the motor. Be sure driven and drive sheaves are in alignment and
parallel.
6. Retighten set screw “B” and replace drive belt on sheaves.
7. Turn motor mount adjusting bolts until belt has approximately 1/2-inch of deflection midway between sheaves
(4 lbs. tension if measured with gauge, see Figure 11).
8. Retighten motor mounting nuts. Belt tension of a new belt will drop rapidly during the first few hours of operation.
9. Check and readjust as needed.
Set Screw “A” Set Screw “B”
Keyway
Moveable
Portion
Figure 11: Checking Drive Belt Tension
Deflection
Driven Sheave
Drive Sheave
Figure 10: Blower Motor Sheave Adjustments and Settings