Secure Owner's Approval; Motor Pulley Adjustment; Belt Adjustment; Press. Drop Versus Supply Air Cfm - York SUNLINE 2000 Installation Instruction

The setting (turns open) for the optional belt-drive supply air
motor pulley can be determined from Table 15.
TABLE 15 - BELT-DRIVE SUPPLY AIR

MOTOR PULLEY ADJUSTMENT

BLOWER DRIVE RANGE (RPM)
TURNS
OPEN*
3 TON
5 780
4 842
3 904
2 966
1 1028
0 1090
*
Pulley can be adjusted in half-turn increments.
OPTIONAL BELT-DRIVE BLOWER
All units with belt-drive blowers have single-speed motors. The
variable pitch pulley on the blower motor can be adjusted to
obtain the desired supply air CFM. Refer to Table 7 for blower
motor and drive data. The tension on the belts should be
adjusted as shown in Figure 7.
FIG. 7 - BELT ADJUSTMENT
Start the supply air blower motor. Adjust the resistances in both
the supply and the return air 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.

SECURE OWNER'S APPROVAL

location of all disconnect switches and the thermostat. Teach him how to start and stop the unit and how to adjust temperature
settings within the limitations of the system.
Unitary Products Group
4 TON 5 TON 6 TON
790 850 900
856 924 970
922 998 1040
988 1072 1110
1054 1246 1180
1120 1220 1250
: When the system is functioning properly, secure the owner's approval. Show him the
To check the supply air CFM after the initial balancing has been
completed:
⁄
1. Remove the (two) 5
" dot plugs from the holes located on
16
the filter access panel side of the unit.
2. Insert at least 8" of 1/4 inch tubing into each of these holes
for sufficient penetration into the air flow on both sides of
the evaporator coil.
NOTE: The tubes must be inserted and held in a position
perpendicular to the air flow so that velocity pres-
sure will not affect the static pressure readings.
3. Using an inclined manometer, determine the pressure drop
across a dry indoor coil. Since the moisture on an indoor
coil may vary greatly, measuring the pressure drop across
a wet coil under field conditions would be inaccurate. To
assure a dry coil, the scroll compressors should be
de-energized while the test is being run.
4. Knowing the pressure drop across a dry coil, the actual
CFM through the unit can be determined from the curve in
Figure 8.
0.7
0.6
0.5
036
0.4
0.3
0.2
0.1
0
750 1250 1750
FIG. 8 - PRESSURE DROP ACROSS A DRY
EVAPORATOR COIL VS SUPPLY AIR CFM,
WITHOUT AIR FILTERS
WARNING: Failure to properly adjust the total system air quan-
tity can result in poor system performance.
5. After readings have been obtained, remove the tubes and
5
seal the holes with the
NOTE: DE-ENERGIZE THE SCROLL COMPRESSORS BE-
FORE TAKING ANY TEST MEASUREMENTS TO
ASSURE A DRY INDOOR COIL.
530.18-N7Y
072
060
048
2250 2750 3250
NOMINAL CFM
⁄
" dot plugs removed in Step 1.
16
3750
15