Supply Air Blower Motor Pulley Adjustment; Typical Motor Mounting Assembly; Pressure Drop Across Dry Coil Vs Supply Air; Hole Locations (Pressure Drop Readings) - York SUNLINE K4EU120A50A Installation Instruction

3. Using an inclined manometer, determine the pressure drop
across a dry evaporator coil. Since the moisture on an
evaporator coil may vary greatly, measuring the pressure
drop across a wet coil under field conditions would be inac-
curate. To assure a dry coil, the refrigerant system should
be de-energized while the test is being run.
4. Knowing the pressure drop across a dry coil, the actual air-
flow through the unit can be determined from the curve in
Figure 7.
If the airflow is above or below the specified valve, the supply
air motor pulley may have to be readjusted. After one hour of
operation, check the belt and pulleys for tightness and align-
ment.
WARNING: Failure to properly adjust the total system air quan-
tity can result in extensive blower damage.
TABLE 3 - SUPPLY AIR BLOWER MOTOR PULLEY
ADJUSTMENT
BLOWER DRIVE RANGE (RPM)
TURNS OPEN* KEU090
650 -850
5
4
3
2
1
0
* Pulleys can be adjusted in half-turn increments.
FIG 6 - TYPICAL MOTOR MOUNTING ASSEMBLY
Unitary Products Group
KEU120
700 - 910
650 700
690 740
730 780
770 830
810 870
850 910
After readings have been obtained, remove the tubes and seal
up the drilled holes in the side panel with
plugs (P/N 029-13880) available through normal parts ordering
procedure.
FIG. 7 - PRESSURE DROP ACROSS A DRY
EVAPORATOR COIL VS SUPPLY AIR CFM
DIMENSIONS (in./mm)
A B
3 / 76 3 / 76
NOTE: DE-ENERGIZE THE REFRIGERANT SYSTEM BEF-
ORE TAKING ANY TEST MEASUREMENTS TO AS-
SURE A DRY EVAPORATOR COIL.
FIG. 8 - HOLE LOCATIONS
(PRESSURE DROP READINGS)
550.39-N4YI
5
" (8mm) dia. dot
16
C D
14 / 356 12 / 305
7