Installation; Step 1 - Perform Jobsite Survey; Step 2 - Place Unit; Step 3 - Roof Mount Unit - Carrier WeatherExpert 48N2 Installation Instructions Manual

FLEXIBLE
CONNECTORS
SUPPLY AND
RETURN
VIBRATION
ISOLATORS
IN ROOF
CURB

INSTALLATION

Step 1 — Perform Jobsite Survey
Complete the following checks before installation.
1. Consult local building codes and the NEC (National Electri-
cal Code) (ANSI/NFPA [American National Standards Insti-
tute/National Fire Protection Association] 70) for special
installation requirements.
2. Determine unit location (from project plans) or select unit
location. Refer to Acoustical Considerations section.
3. Check for possible overhead obstructions which may inter-
fere with unit lifting or rigging.
CAUTION
Do not lift unit with forklift truck. Move unit with overhead
rigging only.
Step 2 — Place Unit
Inspect unit for transportation damage. If any damage is found,
file a claim with the transportation agency.
Provide clearance around and above unit for airflow, safety, and
service access. Do not restrict top (area above condenser fans) in
any way. Allow at least 6 ft on all sides for rated performance,
code compliance, and service. On units equipped with power ex-
haust (PE) option, high velocity air is exhausted out the hood. Unit
should be positioned with at least 10 ft clearance between the ex-
haust hood and any obstruction. See Fig. 2 for multiple unit mini-
mum separation. See Tables 1-5 for additional unit and fan data.
Check unit dimensional drawings on pages 23-25 for unit arrange-
ment and minimum performance and service clearances.
INTAKE
SUPPLY
PLENUM
FAN
SUPPLY AND RETURN
DUCTS LINED WITH
ACOUSTICAL DUCT LINER
Fig. 1 — Acoustical Considerations
Do not install unit in an indoor location. Do not locate air inlets
near exhaust vents or other sources of contaminated air.
Although unit is weatherproof, guard against water from higher
level runoff and overhangs.
Level by using unit frame as a reference.
Step 3 — Roof Mount Unit
Check building codes for weight distribution requirements. Refer
to Acoustical Considerations section. Unit and accessory weights
are shown in Tables 1 and 2. Unit may be mounted on class A, B,
or C roofing material.

ROOF CURB

Assemble and install roof curb as described in instructions shipped
with the accessory. Accessory roof curb and information required
to field fabricate a roof curb is shown in Fig. 3 and 4. Install insu-
lation, cant strips, roofing, and counter flashing as required. For
unit condensate drain to function properly, curb must be level or
within tolerances shown in Fig. 3.
NOTE: Units with double-wall floor design ("Double Wall on-
the-bottom") are not compatible with roof curbs.

STEEL BEAMS

If roof curb is not used, support unit with steel beams along its en-
tire length and then support steel as required. Cross members are
required to support across its width at each lifting lug location; use
more cross members for support as needed. See Fig. 4.
Step 4 — Slab Mount Unit
Provide a level concrete slab that extends beyond unit cabinet at
least 6 inches. Use gravel apron in front of condenser coil air inlet
to prevent grass and foliage from obstructing airflow. Provide a
slab minimum 8 in. thick with sufficient height above grade to al-
low for condensate trap as described in Step 8.
4
DISCHARGE
PLENUM
COMPRESSOR/
CONDENSING
SECTION
ROUND DUCT CONTROLS
RUMBLE BEST
ALL ROOF
PENETRATIONS
SHOULD BE
SEALED
AIR TIGHT