York D*SC360, Руководство по установке

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After the movable flange (or flanges) has been rotated to the
proper number of “turns open”, the set screws should be
tightened against the flats on the barrel to lock the movable
flange in place. If the pulley includes a locking collar, the locking
collar must be loosened to adjust the setting of the movable
flange.
Note the following:
1. The supply air CFM must be within the limitations shown in
Table 1.
2. Both movable flanges on a 2-groove pulley must be
adjusted to the same setting (turns open) to balance the
loading on both belts.
3. All pulleys can be adjusted in half-turn increments.
4. The tension on each belt shall be adjusted per the following
procedure. See Figure 16.
a. Loosen two nuts (A).
b. Adjust by turning (B).
c. Never loosen nuts (C).
d. Using a belt tension checker, apply a perpendicular
force to one belt at the midpoint of the span as shown.
The deflection force should be applied until the speci-
fied deflection distance is obtained.
The deflection distance equals 1/64" per inch of span
length.
To determine the deflection distance from normal posi-
tion use a straight edge from sheave to sheave as a
reference line.
The recommended deflection force is as follows:
e. Tension new belts at the maximum deflection force
recommended for the belt section. Check the belt ten-
sion at lease two times during the first 24 hours of
operation. Any retensioning should fall between the
minimum and maximum deflection force values.
f. After adjusting, retighten nuts (A).
5. All pulleys are factory aligned.
6. All supply air motor pulleys are factory set at 2 “turns open”.
After the pre-start check list has been completed:
1. Start the supply air blowers.
2. Adjust the resistances in both the supply and the return duct
systems to balance the air distribution throughout the
conditioned space. The job specifications may require that
this balancing be done by someone other than the
equipment installer.
To check the supply air CFM after the initial balancing has been
completed.
1. Drill two 5/16" holes (A & B) as shown in Figure 17.
MODEL
TURNS
OPEN
1
RPM
10 15 20
DSC360
6 780 924 -
5 812 962 -
4 844 1000 -
3 876 1038 -
2 908 1076 -
1 940 1114 -
DSC480
6 - 924 -
5 - 962 -
4 - 1000 -
3 - 1038 -
2 - 1076 -
1 - 1114 1189
2
1
Pulleys can be adjusted in half turn increments.
2
Fixed pulleys, no adjustment.
TABLE 7 - SUPPLY AIR SYSTEM ADJUSTMENT
BELT
SECTION
DEFLECTION FORCE (LBS.)
MINIMUM MAXIMUM
“B” 4 5
“C” 11 14
FIG. 16 - TYPICAL MOTOR MOUNTING ASSEMBLY
530.25-N3Y
Unitary Products Group 17