Trane Voyager Commercial - Maintenance Procedures; Fan Belt Adjustment and Inspection

116
RT-SVX34R-EN
Maintenance
Fan Belt Adjustment
The supply fan belts must be inspected periodically to
assure proper unit operation.
Replacement is necessary if the belts appear frayed or
worn. Units with dual belts require a matched set of
belts to ensure equal belt length. When installing new
belts, do not stretch them over the sheaves; instead,
loosen the adjustable motor-mounting base.
Once the new belts are installed, adjust the belt tension
using a Browning or Gates tension gauge (or
equivalent) illustrated in Figure 99, p. 116.
Figure 99. Typical belt tension gauge
Deflection = Belt Span (in.)
64
Deflection = Belt Span (mm)
152
Force Scale
Span Scale
Large
O-Ring
Small
O-Ring
Belt Span
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1. To determine the appropriate belt deflection:
a. Measure the center-to-center distance, in
inches, between the fan sheave and the motor
sheave.
b. Divide the distance measured in Step 1a by 64;
the resulting value represents the amount of
belt deflection for the proper belt tension.
2. Set the large O-ring on the belt tension gauge at the
deflection value determined in Step 1b.
3. Set the small O-ring at zero on the force scale of the
gauge.
4. Place the large end of the gauge on the belt at the
center of the belt span. Depress the gauge plunger
until the large O-ring is even with the of the second
belt or even with a straightedge placed across the
sheaves.
5. Remove the tension gauge from the belt. Notice
that the small O-ring now indicates a value other
than zero on the force scale. This value represents
the force (in pounds) required to deflect the belt(s)
the proper distance when properly adjusted.
6. Compare the force scale reading in step 5 with the
appropriate “force” value in Table 66, p. 117. If the
force reading is outside of the listed range for the
type of belts used, either readjust the belt tension or
contact a qualified service representative.
NNoottee:: The actual belt deflection force must not
exceed the maximum value shown in Table
66, p. 117 .
7. Recheck the new belt's tension at least twice during
the first 2 to 3 days of operation. Readjust the belt
tension as necessary to correct for any stretching
that may have occurred. Until the new belts are
“run in”, the belt tension will decrease rapidly as
they stretch.