CONTENTS
Page
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . . . 1
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-37 I. Step 1 — Provide Unit Support. . . . . . . . . . . . . . . . . 1 II. Step 2 — Field Fabricate Ductwork . . . . . . . . . . . . . 1
III. Step 3 — Install Condensate Drain Line
and External Trap. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 IV. Step 4 — Rig and Place Unit. . . . . . . . . . . . . . . . . . . 2 V. Step 5 — Make Electrical Connections . . . . . . . . . . 7 VI. Step 6 — Adjust Factory-Installed Options . . . . . . 11 VII. Step 7 — Adjust Evaporator-Fan Speed . . . . . . . . 21
PRE-START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38-41
SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41-45
TROUBLESHOOTING. . . . . . . . . . . . . . . . . . . . . . . . . . . .46-49
INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . . . . . . . . CL-1
SAFETY CONSIDERATIONS
Installation and servicing of air-conditioning equipment can be hazardous due to system pressure and electrical compo- nents. Only trained and qualified service personnel should install, repair, or service air-conditioning equipment.
Untrained personnel can perform basic maintenance func- tions of cleaning coils and filters and replacing filters. All other operations should be performed by trained service per- sonnel. When working on air-conditioning equipment, observe precautions in the literature, tags and labels attached to the unit, and other safety precautions that may apply.
Follow all safety codes. Wear safety glasses and work gloves. Use quenching cloth for unbrazing operations. Have fire extinguisher available for all brazing operations.
CAUTION: Ensure voltage listed on unit data plate agrees with electrical supply provided for unit.
WARNING: Before performing service or mainte- nance operations on unit, turn off main power switch to unit and install lockout tag. Electrical shock could cause personal injury.
INSTALLATION
Unit is shipped in the vertical configuration. To convert to horizontal configuration, remove side duct opening covers. Using the same screws, install covers on vertical duct open- ings with the insulation-side down. Seals around duct openings must be tight. See Fig. 1.
Cancels: II 551B-90-6 | II 551B-90-7 |
| 10/15/05 |
I. STEP 1 — PROVIDE UNIT SUPPORT
A. Roof Curb
Assemble and install accessory roof curb in accordance with instructions shipped with curb. Install insulation, cant strips, roofing felt, and counter flashing as shown. Ductwork must be attached to curb. If electric or control power is to be routed through the basepan, attach the accessory thru-the- bottom service connections to the basepan in accordance with the accessory installation instructions. Connections must be installed before unit is set on roof curb.
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 also result in air leaks and poor unit performance.
Curb should be level. This is necessary for unit drain to func- tion properly. Unit leveling tolerances are shown in Fig. 3. Refer to Accessory Roof Curb Installation Instructions for additional information as required.
B. 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 con- denser coil air inlet to prevent grass and foliage from obstructing airflow.
NOTE: Horizontal units may be installed on a roof curb if required.
C. Alternate Unit Support (Curb or Slab Mount)
A non-combustible sleeper rail can be used in the unit curb support area. If sleeper rails cannot be used, support the long sides of the unit with a minimum of 3 equally spaced 4-in. x 4-in. pads on each side.
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 appli- cable fire codes.
A minimum clearance to combustibles is not required around ductwork on vertical discharge units. On horizontal dis- charge units, a minimum clearance of 1 in. is required for the first 12 in. of ductwork. Cabinet return-air static pressure (a negative condition) should not exceed 0.30 in. wg with EconoMi$er IV, or 0.45 in. wg without economizer.
