Carrier Infinity 480CEN024 Installation Instruction page 12

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8. Check for gas leaks at the field-installed and
factory-installed gas lines after all piping connections have
been completed. Use soap-and-water solution (or method
specified by local codes and/or regulations).
Step 9--Install Duct Connections
The unit has duct flanges on the supply- and return - air openings on
the side and bottom of the unit. For downshot applications, the
dnctwork connects to the roof curb (See Fig. 5 and 6 for connection
sizes and locations).
CONFIGURING UNITS FOR DOWNFLOW (VERTICAL)
DISCHARGE
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
Before installing or servicing system, always turn off main
power to system. There may be more than one disconnect
switch.
1. Open all electrical disconnects before starting any service
work.
2. Remove horizontal (metal) duct covers to access vertical
(down flow) discharge duct knockouts in unit base.
3. Use a screwdriver and hammer to remove the panels in the
bottom of the unit base (See Fig. 11).
4. If unit ductwork is to be attached to vertical opening flanges
on the unit base (iackstand applications only), do so at this
time.
PROPERTY DAMAGE HAZARD
Failure to follow this caution may result in property damage.
Collect ALL screws that were removed. Do not leave screws
on rooftop as permanent damage to the roof may occur.
5. It is reconmmnded that the base insulation around the
perimeter of the vertical return-air opening be secured to the
base with aluminum tape. Applicable local codes may
require aluminum tape to prevent exposed fiberglass.
6. Cover both horizontal duct openings with the provided duct
covers. Ensure opening is air- and watertight.
7. After completing unit conversion, perform all safety checks
and power up unit.
NOTE: The design and installation of the duct system must be in
accordance with the standards of the NFPA for installation of
nonresidence-type air conditioning and ventilating systems. NFPA
90A or residence-type, NFPA 90B; and/or local codes and
ordinances.
Adhere to the following criteria when selecting, sizing, and
installing the duct system:
1. Units are shipped for horizontal duct installation (by
removing duct covers).
2. Select and size ductwork, supply-air registers, and
return-air grilles according to American Society of Heating,
Refrigeration and Air Conditioning Engineers (ASHRAE)
recommendations.
Duct Covers
Fig. 11 - 48CE with Duct Covers
On
A05301
3. Use flexible transition between rigid ductwork and unit to
prevent transmission of vibration. The transition may be
screwed or bolted to duct flanges. Use suitable gaskets to en-
sure weather-tight and airtight seal.
4. All units must have field-supplied filters or accessory filter
rack installed in the return-air side of the unit.
Recommended sizes for filters are shown in Table 1.
5. Size all ductwork for maximum required airflow (either
heating or cooling) for unit being installed. Avoid abrupt
duct size increases or decreases or performance may be
affected.
6. Adequately insulate and weatherproof all ductwork located
outdoors. Insulate ducts passing through unconditioned
space, and use vapor barrier in accordance with latest issue
of Sheet Metal and Air Conditioning Contractors National
Association (SMACNA) and Air Conditioning Contractors
of America (ACCA) minimum installation standards for
heating and air conditioning systems. Secure all ducts to
building structure.
7. Flash. weatherproof, and vibration isolate all openings in
building structure in accordance with local codes and good
building practices.
Step 10--Install Electrical Connections
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal injury
or death.
The unit cabinet must have an uninterrupted, unbroken
electrical ground. This ground may consist of an electrical
wire connected to the unit ground screw in the control
compartment, or conduit approved for electrical ground when
installed in accordance with NEC, ANSI/NFPA American
National Standards Institute/National Fire Protection
Association (latest edition) (in Canada, Canadian Electrical
Code CSA (;22.1) and local electrical codes.
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