Unitary products group FF-07, Руководство по установке

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035-18548-001-B-0203
Unitary Products Group 13
SUPPLY AIR BLOWER ADJUSTMENT
The RPM of the supply air blower will depend on the
required CFM, the unit accessories and the static resis-
tances of both the supply and the return air duct sys-
tems. With this information, the RPM for the supply air
blower can be determined from the blower perfor-
mance in Table 6.
Knowing the required blower RPM and the blower
motor HP, the setting (turns open) for the supply air
motor pulley can be determined from Table 5.
* Pulleys can be adjusted in half-turn increments.
Each motor pulley has:
1. A threaded barrel with two flats (or notched
recesses) 180 degrees apart.
2. A movable flange with one set screw.
After the movable flange has been rotated to the
proper number of “turns open”, the set screw should be
tightened against the flat on the barrel to lock the mov-
able flange in place. If the pulley includes a locking col-
lar, 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 2.
2. All pulleys can be adjusted in half-turn increments.
3. The tension on the belt should be adjusted for a
deflection od 3/16 of an inch per foot of belt span
with an applied force of 2 to 3 pounds. This adjust-
ment is made by moving the blower motor mount-
ing plate. Refer to Figure 10. Turning the
adjustment bolt (B) moves the motor mounting
plate up or down. Note - Never loosen the two nuts
(C). Two hex nuts (A) have to be loosened to move
the mounting plate and retightened after the
mounting plate has been moved to the proper posi-
tion.
4. All pulleys are factory aligned.
5. All supply air motor pulleys are factory set at 3
“turns open”.
After the supply air blower motor is operating, 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 inch holes in the side panel as shown
in Figure 11.
2. Insert at least 6” of 1/4 inch tubing into each of
these holes for sufficient penetration into the air
flow on both sides of the indoor coil.
NOTE:
The tubes must be inserted and held in a posi-
tion perpendicular to the air flow so that veloc-
ity pressure will not affect the static pressure
readings.
TABLE 5: SUPPLY AIR BLOWER MOTOR PULLEY
ADJUSTMENT
TURNS
OPEN*
DRIVE RANGE
FF-07
690 - 920
5 690
4 730
3 770
2 815
1 850
0 920
FIGURE 10 - TYPICAL MOTOR MOUNTING
ASSEMBLY
B
A
(DO NOT LOOSEN)
MOTOR
MOTOR MOUNT
C