Fan Belt Adjustment - Belt Drive Units - Trane Precedent WSC060ED Installation, Operation And Maintenance Manual

Start-Up
available stages of cooling & heating), perform these final
checks before leaving the unit:
• Program the Night Setback (NSB) panel (if applicable)
for proper unoccupied operation. Refer to the
programming instructions for the specific panel.
• Verify that the Remote panel "System" selection
switch, "Fan" selection switch, and "Zone
Temperature" settings for automatic operation are
correct.
• Inspect the unit for misplaced tools, hardware, and
debris.
• Verify that all exterior panels including the control
panel doors and condenser grilles are secured in place.
• Close the main disconnect switch or circuit protector
switch that provides the supply power to the unit's
terminal block or the unit mounted disconnect switch.
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

WARNING
Live Electrical Components!
During installation, testing, servicing and
troubleshooting of this product, it may be necessary to
work with live electrical components. Have a qualified
licensed electrician or other individual who has been
properly trained in handling live electrical components
perform these tasks. Failure to follow all electrical
safety precautions when exposed to live electrical
components could result in death or serious injury.
WARNING
Rotating Components!
Disconnect all electric power, including remote
disconnects before servicing. Follow proper lockout/
tagout procedures to ensure the power can not be
inadvertently energized. Failure to disconnect power
before servicing could result in death or serious injury.
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 28, p. 32; adjust the belt tension as follows;
1. To determine the appropriate belt deflection;
32
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 O-
ring is even with the top of the next belt or even with
a straightedge placed across the fan and motor
sheaves. Refer to Figure 28, p.
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
appropriate "force" value listed in
"force" reading is outside the range, readjust the belt
tension.
Note: Actual belt deflection "force" must not exceed the
maximum "force" value shown in.
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"
Figure 28. Belt tension gauge
32.
(Step 5) with the
Table 7, p. 33. If the
RT-SVX39B-EN