Bryant 548D Unit Leveling Tolerances, Ii. - Field Fabricate Ductwork, Iv. - Rig And Place Unit

MAXIMUM ALLOWABLE

DIFFERENCE (in.)

A-B	B-C	A-C
0.5	1.0	1.0

Fig. 2 — Unit Leveling Tolerances

II. STEP 2 — FIELD FABRICATE DUCTWORK

On vertical discharge units, secure all ducts to roof curb and building structure. Do not connect ductwork to unit. For hori- zontal applications, field-supplied flanges should be attached to horizontal discharge openings and all ductwork attached to the flanges. Insulate and weatherproof all external duct- work, joints, and roof openings with counter flashing and mastic in accordance with applicable codes.

Ducts passing through an unconditioned space must be insu- lated 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 ap- plicable fire codes.

A minimum clearance to combustibles is not required around ductwork on vertical discharge units. On horizontal discharge units with electric heat, a minimum clearance of 1 in. is required for the first 12 in. of ductwork. Cabinet return-air static should not exceed –0.35 in. wg with Durablade econo- mizer, –0.30 in. wg with EconoMi$er, or –0.45 in. wg without economizer.

CAUTION: Ensure voltage listed on unit data plate agrees with electrical supply provided for the unit.

III.STEP 3 — INSTALL CONDENSATE DRAIN LINE AND EXTERNAL TRAP

Condensate drain connections are located on the bottom and end of the unit. Unit discharge connections do not determine the use of drain connections; either drain connection can be used in vertical or horizontal applications.

When using the standard end 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 bot- tom connection to the end connection. See Fig. 3. 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. See Fig. 4. 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.).

IV. 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 reference. See Table 1 and Fig. 5 for additional information. Operating weight is shown in Table 1 and Fig. 5.

Lifting holes are provided in base rails as shown in Fig. 5 and 6. Refer to rigging instructions on unit.

Positioning

Maintain clearance around and above unit to provide proper airflow and service access. See Fig. 6.

Position unit on roof curb so that the following clearances are maintained: 1/4-in. clearance between roof curb and base rails on each side and in duct end of unit; 35/16-in. clearance between roof curb and condenser end (see Fig. 1, section C-C).

Do not install unit in an indoor location. Do not locate unit air inlet near exhaust vents or other sources of contami- nated air.

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

After unit is in position, remove polyethylene shipping wrap- per and rigging skid.

DRAIN PLUG

NOTE: Drain plug is shown in factory-installed position.

Fig. 3 — Condensate Drain Connection

NOTE: Trap should be deep enough to offset maximum unit static dif- ference. A 4-in. trap is recommended.

Fig. 4 — External Trap Condensate Drain

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