Installation; Step 1 - Plan For Unit Location; Roof Mount; Step 2 - Plan For Sequence Of Unit Installation - Carrier WeatherExpert 48LC Series Installation Instructions Manual

INSTALLATION

Jobsite Survey
Complete the following checks before installation.
1. Consult local building codes and the NEC (National Elec-
trical Code) ANSI/NFPA 70 for special installation
requirements.
2. Determine unit location (from project plans) or select unit
location.
3. Check for possible overhead obstructions which may inter-
fere with unit lifting or rigging.
Step 1 — Plan for Unit Location
Select a location for the unit and its support system (curb or other)
that provides for the minimum clearances required for safety. This
includes the clearance to combustible surfaces, unit performance
and service access below, around and above unit as specified in
unit drawings. See Fig. 5, 10, and 15.
NOTE: Consider also the effect of adjacent units.
Be sure that the unit is installed such that snow will not block the
combustion air intake or flue outlet.
Unit may be installed directly on wood flooring or on Class A, B,
or C roof-covering material when roof curb is used.
Do not install unit in an indoor location. Do not locate 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 Combustion and
Ventilation) of the National Fuel Gas Code, ANSI Z223.1 (Ameri-
can National Standards Institute) and NFPA (National Fire Protec-
tion Association) 54 TIA-54-84-1. In Canada, installation must be
in accordance with the CAN1-B149 installation codes for gas
burning appliances.
Although unit is weatherproof, avoid locations that permit water
from higher level runoff and overhangs to fall onto the unit.
Locate mechanical draft system flue assembly at least 4 ft (1.2 m)
from any opening through which combustion products could enter
the building, and at least 4 ft (1.2 m) from any adjacent building
(or per local code). Locate the flue assembly at least 10 ft (3.05 m)
from an adjacent unit's fresh air intake hood if within 3 ft (0.91 m)
of same elevation (or per local code). When unit is located adja-
cent to public walkways, flue assembly must be at least 7 ft
(2.1 m) above grade.
Select a unit mounting system that provides adequate height to al-
low installation of condensate trap per requirements. Refer to
Step 11 — Install External Condensate Trap and Line for required
trap dimensions.

ROOF MOUNT

Check building codes for weight distribution requirements. Unit
operating weight is shown in Table 2.
Step 2 — Plan for Sequence of Unit Installation
The support method used for this unit will dictate different se-
quences for the steps of unit installation. For example, on curb-
mounted units, some accessories must be installed on the unit be-
fore the unit is placed on the curb. Review the following for rec-
ommended sequences for installation steps.

CURB-MOUNTED INSTALLATION

1. Install curb
2. Install field-fabricated ductwork inside curb
3. Install thru-base service connection fittings (affects curb and
unit)
4. Rig and place unit
5. Remove top skid
6. Install outside air hood
7. Install smoke detector tube
8. Install combustion air hood
9. Install flue hood
10. Install gas piping
11. Install condensate line trap and piping
12. Make electrical connections
13. Install other accessories

PAD-MOUNTED INSTALLATION

1. Prepare pad and unit supports
2. Rig and place unit
3. Remove duct covers and top skid
4. Install smoke detector return air sensor tube
5. Install field-fabricated ductwork at unit duct openings
6. Install outside air hood
7. Install combustion air hood
8. Install flue hood
9. Install gas piping
10. Install condensate line trap and piping
11. Make electrical connections
12. Install other accessories

FRAME-MOUNTED INSTALLATION

Frame-mounted applications generally follow the sequence for a
curb installation. Adapt as required to suit specific installation
plan.
Step 3 — Inspect Unit
Inspect unit for transportation damage. File any claim with trans-
portation agency.
Confirm before installation of unit that voltage, amperage and cir-
cuit protection requirements listed on unit data plate agree with
power supply provided.
On units with hinged panel option, check to be sure all latches are
tight and in closed position.
Locate the carton containing the outside air hood parts; see Fig. 21
and 24. Do not remove carton until unit has been rigged and locat-
ed in final position.
Step 4 — Provide Unit Support

ROOF CURB MOUNT

Accessory roof curb details and dimensions are shown in
Fig. 17-19. Assemble and install accessory roof curb in accor-
dance with instructions shipped with the curb.
NOTE: 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. 17-19. Improperly applied gasket can also result in air leaks
and poor unit performance.
19