Air Balancing; Sheave Adjustment - Daikin Enfinity Installation And Maintenance Manual

Air balancing

Unit sizes 072 thru 290 are supplied with a variable pitch
motor sheave to aid in airflow adjustment.
When the final adjustments are complete, the current draw
of the motors should be checked and compared to the full
load current rating of the motors. The amperage must not
exceed the service factor stamped on the motor nameplate.

Sheave Adjustment

Adjusting Single Groove Sheave
1 . All sheaves should be mounted on the motor or
driving shaft with the setscrew "X" toward the motor
2 . Fit shaft key "D" between sheave and shaft, and
lock setscrew "X" in place. Wrench torque 110 in.-lb.
minimum - 130 in.-lb. maximum.
3 . Be sure both driving and driven sheaves are in
alignment and that shafts are parallel. Total axial
and parallel misalignment must not exceed 1/4°
4 . Loosen setscrew "Y" in moving flange of sheave until
movable flange is free to rotate.
5 . Adjust sheave pitch diameter for desired speed by
opening rotating parts by half or full turn increments from
closed position. Do not open more than five full turns.
6 . Tighten setscrew "Y" to 110 in.-lb. to 130 in.-lb. with
setscrew "Y" located over center of casts flats on
barrel of sheaves fixed component.
7 . Put on belts and adjust tension. (Do not force belts
over grooves.) Check setscrews and belt tension after
24 hours of operation.
Figure 6: Sheave adjustment detail - single groove
X
Adjusting 2-Groove Sheaves
1 . All sheaves should be mounted on the motor or
driving shaft with the setscrew "X" toward the motor
1 . Loosen setscrews "Y" in moving flanges and pull out
key "E". (This key projects a small amount to provide a
grip for removing).
2 . Rotate both movable flanges inward until they touch
the center flange.
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3 .
4 .
5 .
6 .
7 .
Figure 7: Sheave adjustment detail - two groove
Y
Figure 8: Drive belt adjustment
D
h =
t =
7
i
nstallation
Open each movable flange until its notch is adjacent to
the notch on the center flange. Be certain that neither
movable flange is opened more than one full turn.
Open each movable flange the same number of full or
half turns until the desired number of turns is obtained.
Do not open more than five full turns.
CAUTION
Failure to adjust both equally may cause excessive vibration and
blower assembly failure.
Replace key "E" and tighten setscrews "Y". Wrench
torque 110 in.-lb. minimum - 130 in.-lb. maximum.
Put on belts and adjust belt tension.(Do not force belts
over flanges).
Be sure that all keys are in place and that all setscrews
are torqued properly before starting drive. Check
setscrews and belt tension after 24 hours of operation.
Y
X
D
t
Where: t = Span length, inches (mm)
64
C = Center distance, inches (mm)
d = Smaller sheave diameter, inches (mm)
) (
D-d
h = Deflection height, inches (mm)
C 2 -
2
Note: The ratio of deflection to belt span is 1:64.
LARGE VERTICAL WSHP IM 1059-12
C
onsiderations
OD notched here
.
Y
E
D
Key "E" projects to
provide a grip for
removing
d
C