Carrier 48TF004-007 Field Fabricate Ductwork Secure all, Rig and Place Unit Inspect unit for

Fig. 1 — Horizontal Conversion Panels

Curb should be level. Unit leveling tolerances are shown in Fig. 3. This is necessary for unit drain to function properly. Re- fer to Accessory Roof Curb Installation Instructions for addi- tional 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 condenser coil air inlet to prevent grass and foliage from obstructing airflow.

NOTE: Horizontal units may be installed on a roof curb if required.

Step 2 — Field Fabricate Ductwork — Secure all

ducts to roof curb and building structure on vertical ducted units. Do not connect ductwork to unit. For horizontal applica- tions, 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 openings with counter flashing and mastic in accordance with applicable codes.

Ducts passing through an unconditioned space must be in- sulated 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 applica- ble fire codes.

A minimum clearance is not required around ductwork. Cabinet return air static shall not exceed –.20 in. wg with EconoMi$er, –.35 in. wg with Durablade economizer, or –.45 in. wg without economizer.

These units are designed for a minimum continuous heating return-air temperature of 50 F (dry bulb), or an intermittent op- eration down to 45 F (dry bulb), such as when used with a night set-back thermostat.

Step 3 — Install External Trap for Condensate Drain — The unit’s 3/4-in. condensate drain connections are located on the bottom and side of the unit. Unit discharge con- nections do not determine the use of drain connections; either drain connection can be used with vertical or horizontal applications.

When using the standard side drain connection, make sure the plug (Red) in the alternate bottom connection is tight before installing the unit.

To use the bottom drain connection for a roof curb installa- tion, relocate the factory-installed plug (Red) from the bottom connection to the side connection. See Fig. 4. The piping for the condensate drain and external trap can be completed after the unit is in place.

All units must have an external trap for condensate drain- age. Install a trap at least 4-in. deep and protect against freeze- up. If drain line is installed downstream from the external trap, pitch the line away from the unit at 1 in. per 10 ft of run. Do not use a pipe size smaller than the unit connection (3/4 in.).

Step 4 — Rig and Place Unit — Inspect unit for

transportation damage. 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. Rollers may be used to move unit across a roof. Level by using unit frame as a refer- ence. See Table 1 and Fig. 5 for additional information.

Lifting holes are provided in base rails as shown in Fig. 6. Refer to rigging instructions on unit.

All panels must be in place when rigging.

POSITIONING — Maintain clearance around and above unit to provide minimum distance from combustible materials, proper airflow, and service access. See Fig. 6. A properly posi- tioned unit will have the following clearances between unit and roof curb: 1/4-in. clearance between roof curb and base rails on each side and duct end of unit; 1/4-in. clearance between roof curb and condenser coil end of unit. (See Fig. 2, section C-C.)

Do not install unit in an indoor location. Do not locate unit air inlets near exhaust vents or other sources of contaminated air.

Be sure that unit is installed such that snow will not block the combustion intake or flue outlet.

2