Install Outside Air Hood, Positioning on Curb

Positioning on Curb —

Position unit on roof curb so that the following clearances are maintained: 1/4 in. (6.4 mm) clearance between the roof curb and the base rail inside the front and rear, 0.0 in. clearance between the roof curb and the base rail inside on the duct end of the unit. This will result in the distance between the roof curb and the base rail inside on the condenser end of the unit being approximately equal to Fig. 3, section C-C.

Although unit is weatherproof, guard against water from higher level runoff and overhangs.

!CAUTION

UNIT DAMAGE HAZARD

Failure to follow this caution may result in equipment damage.

All panels must be in place when rigging. Unit is not designed for handling by fork truck.

After unit is in position, remove rigging skids and shipping materials.

Step 7 — Convert to Horizontal and Connect Ductwork (when required)

Unit is shipped in the vertical duct configuration. Unit without factory-installed economizer or return air smoke detector option may be field-converted to horizontal ducted configuration. To convert to horizontal configuration, remove screws from side duct opening covers and remove covers. Using the same screws, install covers on vertical duct openings with the insulation-side down. Seals around duct openings must be tight. See Fig. 6.

C06108

Fig. 6 - Horizontal Conversion Panels

Field-supplied flanges should be attached to horizontal duct openings and all ductwork should be secured to the flanges. Insulate and weatherproof all external ductwork, joints, and roof or building openings with counter flashing and mastic in accordance with applicable codes.

Do not cover or obscure visibility to the unit’s informative data plate when insulating horizontal ductwork.

Step 8 — Install Outside Air Hood

The outdoor hood components are shipped in a box located in the unit return air compartment behind the outdoor-ar opening access panel (or economizer). Access is through the filter access panel. See Fig. 7.

FILTER ACCESS PANEL

COMPRESSOR	551J	j
OUTDOOR-AIR OPENING AND	551J	j
ACCESS PANEL
INDOOR COIL ACCESS PANEL
	C06023

Fig. 7 - Typical Access Panel Locations

1.To remove the existing unit filter access panel, raise the panel and swing the bottom outward. The panel is now disengaged from the track and can be removed.

2.To remove the component box from its shipping posi- tion, remove the screw holding the hood box bracket to the top of the economizer. Slide the hood box out of the unit. See Fig. 8.

			x
		o
o		B		HOOD BOX
H	od			HOOD BOX
H				BRACKET
				BRACKET

C06024

Fig. 8 - Hood Box Removal

Motorized 2-Position Damper Hood —

1.Assemble outdoor-air hood top and side plates as shown in Fig. 9. Install seal strips on hood top and sides. Put aside screen retainer and screws for later assembly.

2.Fasten hood top and side plate assembly to unit with screws provided. See Fig. 9.

3.Slide outdoor-air inlet screen into screen track on hood side plates. While holding screen) in place, fasten screen retainer to hood using screws provided.

4.Replace filter access panel. See Fig. 7.