Carrier 48SX024-048 - Manual (Page 10)

RECEIVING AND INSTALLATION
Step 1 - Check Equipment
IDENTIFY UNIT — The unit model number and serial num­
ber are stamped on unit identification plate. Check this
information against shipping papers and job data.
INSPECT SHIPMENT — Inspect for shipping damage while
unit is still on shipping pallet. If unit appears to be dam­
aged or is torn loose from its anchorage, have it examined
by transportation inspectors before removal. Forward claim
papers directly to transportation company. Manufacturer is
not responsible for any damage incurred in transit.
Check all items against shipping list. Immediately notify
the nearest Carrier Air Conditioning office if any item is
missing.
To prevent loss or damage, leave all parts in original pack­
ages until installation.
Step 2 - Provide Unit Support
ROOF CURB — Install accessory roof curb in accordance
with instructions shipped with curb. See Fig. 10 for roof
curb dimensions. Install insulation, cant strips, roofing, and
flashing. Ductwork must be attached to curb.
IMPORTANT: The gasketing of the unit to the roof
curb is critical for a watertight seal. Install gasketing
material supplied with the roof curb. Improperly ap­
plied gasketing can also result in air leaks and poor
unit performance.
Curb should be level to within Vi inch. This is necessary
for unit drain to function properly. Refer to accessory roof
curb installation instructions for additional information as
required.
SLAB MOUNT — Place the unit on a solid, level concrete
pad that is a minimum of 4 in. thick with 2 in. above grade.
The slab should be flush on the front of the unit (to allow
condensate drain installation) and should extend 2 in. on
the three remaining sides of the unit. See Fig. 11. Install a
6-in. gravel apron in front of condenser-air inlets to prevent
obstruction of airflow by grass or shrubs. Do not secure the
unit to the slab except when required by local codes.
FLUSH MOUNT — Place side of unit with duct panel flush
against transition. On units with optional base rails, the skirt
on duct-panel side of unit can be removed or relocated to
allow unit to be mounted flush against transitions that ex­
tend below basepan of unit. To move skirt, proceed as
follows:
1. Remove 4 screws holding skirt to base rail Retain screws.
2. Remove skirt or slide skirt inwards until alternate clear­
ance holes align with base rails.
3. Secure with screws removed in Step 1. Holes align with
base rails.
To remove wood support under unit (with base rail only),
loosen 4 screws above rigging holes and slide assembly out
through rectangular hole.
Step 3 — Field Fabricate Ductwork — Secure all
ducts to roof curb and building structure on vertical dis­
charge units. Do not connect ductwork to unit. For horizon­
tal applications, field-supplied flanges should be attached
to horizontal discharge 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
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 ap­
plicable fire codes.
A minimum clearance is not required around ductwork.
Cabinet return-air static shall not exceed — .25 in. wg.
Step 4 — Provide Clearances — The required min­
imum operating and service clearances are shown in
Fig. 2-9. Adequate combustion, ventilation, and condenser
air must be provided.
A CAUTION
Do not restrict condenser airflow. An air restriction at
either the outdoor-air inlet or the fan discharge can be
detrimental to compressor life.
The condenser fan pushes air through the condenser coil
and discharges it through the bank of louvers in the top
cover, the decorative grille on the right side of the unit, and
the compressor access panel. Be sure that the fan discharge
does not recirculate to the condenser coil. Do not locate the
unit in either a corner or under an overhead obstruction.
The minimum clearance under a partial overhang (such as a
normal house overhang) is 48-in. above the unit top. The
maximum horizontal extension of a partial overhang must
not exceed 48 inches.
Do not place the unit where water, ice, or snow from an
overhang or roof will damage or flood the unit. Do not in­
stall the unit on carpeting, tile, or other combustible mate­
rials. The unit may be installed on wood flooring or on
Class A, B, or C roof covering materials.
Step 5 — Rig and Place Unit
A CAUTION
When installing the unit on a rooftop, be sure the roof
will support the additional weight. Refer to Fig. 2-9
for corner weight information.
Use spreader bars or crate top when rigging the unit. The
units must be rigged for lifting as shown in Fig. 12 and 13
Refer to Tables 1 and 2 for operating weight and to Fig. 2-9
for corner weights. Use extreme caution to prevent damage
when moving the unit. Unit must remain in an upright po­
sition during all rigging and moving operations. The unit
must be level for proper condensate drainage; therefore, the
ground-level pad or accessory roof curb must be level be­
fore setting the unit in place. When a field-fabricated sup­
port is used, be sure that the support is level and properly
supports the unit.
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