
581B,C
C06108
Fig. 1 --- Horizontal Conversion Panels
Step 1 —Provide Unit Support
Roof Curb
Assemble and install accessory roof curb in accordance with instructions shipped with curb. (See Fig. 2.) Install insulation, cant strips, roofing felt, and counter flashing as shown. Ductwork must be attached to curb, not to the unit. If electric control power or gas service is to be routed through the basepan, attach the accessory
IMPORTANT: The gasketing of the unit to the roof curb is critical for a watertight seal. Install gasket supplied with the roof curb as shown in Fig. 2. Improperly applied gasket can result in air leaks and poor unit performance.
Curb should be level. Unit leveling tolerances are shown in Fig.
3.This is necessary for unit drain to function properly. Refer to Accessory Roof Curb Installation Instructions for additional information as required.
Slab Mount (Horizontal Units Only)
Provide a level concrete slab that extends a minimum of 6 in. beyond unit cabinet. Install a gravel apron in front of
NOTE: Horizontal units may be installed on a roof curb if required.
Alternate Unit Support
When the curb or adapter cannot be used, support unit with sleeper rails using unit curb or adapter support area. If sleeper rails cannot be used, support the long sides of the unit with a minimum of 3 equally spaced
Step 2 —Field Fabricate Ductwork
Secure all ducts to roof curb and building structure on vertical discharge units. Do not connect ductwork to unit. For horizontal applications,
Ducts passing through an unconditioned space must be insulated and covered with a vapor barrier.
If a plenum return is used on a vertical unit, the return should be ducted through the roof deck to comply with applicable fire codes.
A minimum clearance is not required around ductwork. Cabinet
These units are designed for a minimum continuous
To operate at lower
Step 3 —Install External Trap for Condensate Drain
The unit’s
When using the standard side drain connection, ensure the plug (Red) in the alternate bottom connection is tight before installing the unit.
To use the bottom drain connection for a roof curb installation, relocate the
All units must have an external trap for condensate drainage. Install a trap
Step 4 —Rig and Place Unit
Inspect unit for transportation damage, and file any claim with transportation agency. Keep unit upright and do not drop. Spreader bars are not required if top crating is left on unit, and rollers may be used to move unit across a roof. Level by using unit frame as a reference. See Table 1 and 2 and Fig. 6 for additional information. Operating weight is shown in Table 1 and 2 and Fig. 6.
Lifting holes are provided in base rails as shown in Fig. 8 and 9. Refer to rigging instructions on unit.
!WARNING
PROPERTY DAMAGE HAZARD
Failure to follow this warning could result in personal injury, death and property damage.
All panels must be in place when rigging and lifting.
Positioning
Maintain clearance around and above unit to provide minimum distance from combustible materials, proper airflow, and service access. (See Fig. 7, 8 and 9.)
Position unit on roof curb so that the following clearances are maintained: 1/4 in. 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. 2, section
Do not install unit in an indoor location. Do not locate unit air inlets near exhaust vents or other sources of contaminated air.
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