York Sun Select YV28, Manual

Page: 78 / 110

Figure 65: Top view
Figure 66: Side view
Item Description
A L-bolt
B Adjustable top nut
C Adjustable lower nut
3. To adjust the belt tension using the
adjustment of nuts complete the following
steps:
a. To increase belt tension, clear the lower
nuts (C) away from bracket and turn the
top nuts (B) against the bracket.
b. To decrease belt tension, clear the top
nuts (B) away from bracket and turn the
lower nuts (C) against the bracket.
Note: For two-belt applications, adjust
the two nut/bolt assemblies so that equal
tension is obtained for both belts
Note: New belts should be tensioned
to the maximum deflection force
recommended for the belt section. Table
58 contains the values to be used after
break-in of new belts.
Figure 67: Measuring belt tension
4. Measure belt tension:
a. Use a belt tension checker to apply
a perpendicular force to one belt at
the midpoint of the span as shown in
Figure 67. To determine the deflection
to determine the deflection adjacent
belt (if applicable) or use a straight edge
from sheave to sheave as a reference
line.
b. Increase applied force until a deflection
distance of 0.4 in. is obtained and
compare the measured deflection force
in Table 58.
c. Adjust belt tension until recommended
deflection force is measured.
d. After belt(s) have been tensioned
properly, move all nuts (B or C) against
bracket.
5. After belt(s) have been tensioned properly,
move all nuts (B or C) against bracket
Installation Manual: YORK
®
Sun™ Select YV28 to YV50
78
Johnson Controls Ducted Systems