Carrier 50LJ008-014 - Manual (Page 2)

ROOF CURB — Assemble and install accessory roof curb
in accordance with instructions shipped with curb. See
Fig. 2. Install insulation, cant strips, roofing and counter
flashing as shown. Ductwork must be attached to curb, not
to unit. If electric or control power is to be routed through
the curb, attach the accessory thru~the-curb service connec­
tion plates to the roof curb in accordance with the accessory
installation instructions. Connection plates must be in­
stalled before unit is set on roof curb.
Step 1 — Provide Unit Support
IMPORTANT: The gasketing of the unit to the roof
curb is critical for water integrity. Install gasket sup­
plied with the roof curb as shown in Fig. 2. Improp­
erly applied gasket can also result in air leaks and
poor unit performance.
Curb should be level. This is necessary for unit drain to
function properly. Unit leveling tolerances are shown in
Fig. 3. Refer to Accessory Roof Curb Installation Instruc­
tions for additional information as required.
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 outdoor-coil air
inlet to prevent grass and foliage from obstructing airflow.
NOTE: Horizontal units may be installed on a roof curb if
required.
Step 2 — Field Fabricate Ductwork — On verti­
cal discharge units, secure all ducts to roof curb and build­
ing 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
insulated and covered with a vapor barrier.
If plenum return is used on a vertical unit, the return should
be ducted through the roof deck to comply with applicable
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 one in. is required
for the first 12 in. of ductwork. Cabinet return-air static
shall not exceed —.35 in. wg with economizer or —.45 in.
wg without economizer
Step 3 — Install External Trap for Condensate
Drain — All units must have an external trap added. A
y4-in. NPT connection is located on the side of the unit.
Use a trap at least 4-in. deep, and protect against freeze-up.
See Fig. 4.
If drain line is run to a drain, pitch line away from unit at
one in. per 10 ft of run. Do not use a pipe size smaller than
the unit connection.
Step 4 — Rig and Place Unit — inspect unit for
transportation damage. File any claim with transportation
agency. Keep unit upright and do not drop. Spreader bars
are not required i.^’ top crpting is left on unit. Rollers may be
used to move unit across a roof. Level by using unit frame
as a reference. See Table 1 and Fig 5 for additional infor­
mation. Operating weight is shown in Table 1 and Fig. 5.
Lifting holes are provided in base rails as shown in Fig.
5 and 6. Refer to rigging instructions on unit.
A CAUTION
I______ All panels must be in place when rigging._________ |
POSITIONING — Maintain clearance around and above
unit to provide proper airflow and service access. See
Fig. 6
Position unit on roof curb so that the following clear­
ances are maintained: ‘A-in. clearance between roof curb
and base rails on each side and front of unit; U/32-in. clear­
ance between roof curb and rear of unit (see Fig. 2, section
C-C).
Do not install unit in an indoor location. Do not locate
unit air inlet near exhaust vents or other sources of contam­
inated air.
Although unit is weatherproof, guard against water from
higher level runoff and overhangs.
After unit is in position, remove polyethylene shipping
wrapper and rigging skid.
Step 5 — Make Electrical Connections
A WARNING
Unit cabinet must have an uninterrupted, unbroken elec­
trical ground to minimize the possibility of personal in­
jury if an electrical fault should occur. This ground may
consist of electrical wire connected to unit ground lug
in control compartment, or conduit approved for elec­
trical ground when installed in accordance with NEC
(National Electrical Code) ANSI (American National
Standards Institute) /NFPA (National Fire Protection As­
sociation) 70-1987 and local electrical codes. Failure
to follow this warning could result in the installer be­
ing liable for personal injury of others.
FIELD POWER SUPPLY - All units except 208/230-v
units are factory wired for the voltage shown on the name­
plate. If the 208/230-v unit is to be connected to a 208-v
power supply, the transformer must be rewired by moving
the black wire from the 230-v red wire on the transformer
and connecting it to the 200-v blue wire from the trans­
former. The end of the red wire then must be insulated.
Refer to unit label diagram for additional information.
Pigtails are provided for field wire connections. Use factory-
supplied splices or UL (Underwriters’ Laboratories) ap­
proved copper/aluminum connector.
When installing units, provide a disconnect per NEC.
All field wiring must comply with NEC and local require­
ments. In Canada, electrical connections must be in accor­
dance with CSA (Canadian Standards Association) C22.1
Canadian Electrical Code Part One.
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