York SUNLINE K4EU120A50A - Manual (Page 7)

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.
After readings have been obtained, remove the tubes and seal
up the drilled holes in the side panel with
5
16
" (8mm) dia. dot
plugs (P/N 029-13880) available through normal parts ordering
procedure.
Unitary Products Group 7
550.39-N4YI
TURNS OPEN*
BLOWER DRIVE RANGE (RPM)
KEU090 KEU120
650 -850 700 - 910
5 650 700
4 690 740
3 730 780
2 770 830
1 810 870
0 850 910
* Pulleys can be adjusted in half-turn increments.
TABLE 3 - SUPPLY AIR BLOWER MOTOR PULLEY
ADJUSTMENT
FIG 6 - TYPICAL MOTOR MOUNTING ASSEMBLY
FIG. 7 - PRESSURE DROP ACROSS A DRY
EVAPORATOR COIL VS SUPPLY AIR CFM
FIG. 8 - HOLE LOCATIONS
NOTE: DE-ENERGIZE THE REFRIGERANT SYSTEM BEF-
ORE TAKING ANY TEST MEASUREMENTS TO AS-
SURE A DRY EVAPORATOR COIL.
(PRESSURE DROP READINGS)
DIMENSIONS (in./mm)
A B C D
3 / 76 3 / 76 14 / 356 12 / 305