035-18200-000-B-1102
12
Unitary Products Group
NOTE:
These coils can only be piped from one side of
the unit.
DRAIN CONNECTION
The drain line MUST be trapped because the coil is
located on the negative side of the supply air blower,
and it must be protected from freezing temperatures.
A 7/8” OD drain connections extends through right
hand side of the cabinet. Refer to Figure 13 for recom-
mended drain piping.
The drain connection is located on the same side of the
unit as the refrigerant connections. The line should be
insulated where moisture drippage will be objection-
able or cause damage to the area.
The 3” dimension must equal or exceed the negative
static pressure developed by the supply air blower. If it
does not the condensate will not drain properly and
may overflow the drain pan. The trap must be at least
2-1/2” deep to maintain a water seal under all operat-
ing conditions, especially during blower start-up.
NOTE:
The unit may have to be raised off the floor to
allow enough height for the trap.
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 settings (turns open) for the supply air
motor pulley can be determined from Table 6.
Each motor pulley has:
1.
A threaded barrel with two flats (or notched
recesses 180° 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
collar, 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 7 and 8.
2.
All pulleys can be adjusted in half turn increments.
3.
The tension on the belt should be adjusted for a
deflection of 3/16” per foot of belt span with an
applied force of 2 to 3 pounds. This adjustment is
made by moving the blower motor mounting plate.
Refer to Figure 14. Turning the adjustment bolt (B)
moves the motor mounting plate up or down. Two
hex nuts (A have to be loosened to move the
mounting plate and retighten after the mounting
plate has been moved to the proper position.
NOTE:
Never loosen the two nuts (C) (shown in Fig.
14).
4.
All pulleys are factory aligned.
5.
All supply air motor pulleys are factory set at 3
“turns open”.
FIGURE 13: RECOMMENDED DRAIN PIPING
5 "
2 - 1 / 2 "
P L A S T I C
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