Installation; Step 1 - Provide Unit Support; Roof Curb; Alternate Unit Support - Carrier WeatherMaker 48A020 Installation Instructions Manual

INSTALLATION

CAUTION
Ensure clearances are in accordance with local installation
codes, the requirements of the gas supplier and the manu-
facturer's installation Instructions.
ATTENTION
Assurez-vous que les dégagements sont conformes aux
codes d'installation locaux, aux exigences du fournisseur de
gaz et aux instructions d'installation du fabricant.
Installation of this furnace at altitudes above 2000 ft (610 m)
shall be made in accordance with the Listed High Altitude
Conversion Kit available with this furnace.
L'installation de ce générateur de chaleur à des altitudes
supérieures à 2000 pi (610 m) doit être effectuée conformé-
ment aux instructions accompagnant la trousse de conversion
pour haute altitude fournie avec cet appareil.
Step 1 — Provide Unit Support
CAUTION
1. All panels must be in place when rigging or damage to
unit may occur.
2. Unit is not designed for handling by fork truck. Damage
to unit may occur.
ROOF CURB — For vertical discharge units, assemble or install
accessory roof curb in accordance with instructions shipped with
this accessory. See Fig. 2-4. Install insulation, cant strips, roofing,
and counter flashing as shown. Ductwork can be installed to roof
curb before unit is set in place. Curb should be level. This is neces-
sary to permit unit drain to function properly. Unit leveling toler-
ance is shown in Fig. 2-4. Refer to Accessory Roof Curb Installa-
tion Instructions for additional information as required. When ac-
cessory roof curb is used, unit may be installed on class A, B, or C
roof covering material.
IMPORTANT: The gasketing of the unit to the roof curb is
critical for a watertight seal. Install gasket with the roof curb
as shown in Fig. 2-4. Improperly applied gasket can also result
in air leaks and poor unit performance.
ALTERNATE UNIT SUPPORT — When the preferred curb or
slab mount cannot be used, support unit with sleepers on perime-
ter, using unit curb support area. If sleepers cannot be used, sup-
port long sides of unit (refer to Fig. 5-13) with a minimum number
of 4-in. x 4-in. pads spaced as follows: 48A20-035 units require 3
pads on each side; 48A040-050 units require 4 pads on each side;
48A060 units require 6 pads on each side. Unit may sag if support-
ed by corners only.
Step 2 — Rig and Place Unit —
portation damage. See Tables 1-6 for physical data and specifica-
tions. File any claim with transportation agency.
Do not drop unit; keep upright. Use spreader bars over unit to pre-
vent sling or cable damage. This unit must be handled with a
crane and cannot be handled by a fork truck. Level by using unit
frame as a reference; leveling tolerance is shown in Fig. 2-4. See
Fig. 14 for additional information. Unit operating weight is shown
in Table 2.
NOTE: On retrofit jobs, ductwork may be attached to the old unit
instead of a roof curb. Be careful not to damage ductwork when
removing old unit. Attach existing ductwork to roof curb instead
of unit.
Four lifting lugs are provided on the unit base rails as shown in
Fig. 5-13. Refer to rigging instructions on unit.
POSITIONING — Maintain clearance, per Fig. 5-13, around and
above unit to provide minimum distance from combustible mate-
rials, proper airflow, and service access.
Do not install unit in an indoor location. Do not locate unit air
inlets near exhaust vents or other sources of contaminated air. For
proper unit operation, adequate combustion and ventilation air
must be provided in accordance with Section 5.3 (Air for Com-
bustion and Ventilation) of the National Fuel Gas Code, ANSI
Z223.1 (American National Standards Institute).
Although unit is weatherproof, guard against water from higher
level runoff and overhangs.
Locate mechanical draft system flue assembly at least 4 ft from
any opening through which combustion products could enter the
building, and at least 4 ft from any adjacent building. When unit is
located adjacent to public walkways, flue assembly must be at
least 7 ft above grade.
ROOF MOUNT — Check building codes for weight distribu-
tion requirements. See Fig. 14. Unit operating weight is shown
in Table 2.
4
Inspect unit for trans-
Instructions continued on page 21.