42
RT-SVX25C-EN
Maintenance
WARNING
Rotating Components!
During installation, testing, servicing and troubleshooting of this product it may be necessary to
measure the speed of rotating components. Have a qualified or licensed service individual who
has been properly trained in handling exposed rotating components, perform these tasks.
Failure to follow all safety precautions when exposed to rotating components could result in
death or serious injury.
Make sure all personnel are standing clear of the unit before proceeding. The system components
will start when the power is applied.
Fan Belt Adjustment - Belt Drive Units
The 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 removing or installing the new belts, do not stretch them over the sheaves. Loosen the belts
using the belt tension adjustment bolts on the motor mounting base.
Once the new belts are installed, using a Browning or Gates tension gauge (or equivalent)
illustrated in
Figure 21, p. 43
; adjust the belt tension as follows;
1.
To determine the appropriate belt deflection;
a. Measure the center-to-center shaft distance (in inches) between the fan and motor sheaves.
b. Divide the distance measured in Step 1a by 64; the resulting value represents the amount
of belt deflection that corresponds to 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 plunger.
4. Place the large end of the gauge at the center of the belt span; then depress the gauge plunger
until the large Oring is even with the top of the next belt or even with a straightedge placed
across the fan and motor sheaves. Refer to
Table 9, p. 43
.
5. Remove the belt tension gauge. The small O-ring now indicates a number other than zero on
the plunger’s force scale. This number represents the force (in pounds) required to give the
needed deflection.
6. Compare the “force” scale reading (Step 5) with the appropriate “force” value listed in
Table 9,
p. 43
If the “force” reading is outside the range, readjust the belt tension.
Note:
Actual belt deflection “force” must not exceed the maximum “force” value shown in
Table 9, p. 43
.
7.
Recheck the belt tension at least twice during the first 2 to 3 days of operation. Belt tension may
decrease until the new belts are “run in”.
