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48VGUK: Installation Instructions
CAUTION
!
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.
3. For single-phase models only, on the discharge side only, remove
the insulation covering the downshot (plastic) knockout. Insulation
is held in place with aluminum tape. Please note that large chassis
units have 2 pieces of insulation, and only the piece over the
downshot knockout needs to be removed. Discard insulation.
4. To remove the downshot (plastic) knockouts for both supply and
returns, break front and right side connecting tabs with a
screwdriver and hammer. Push cover down to break rear and left
side tabs. These plastic knockouts are held in place with tabs
similar to an electrical knockout. Discard plastic knockout covers.
5. Set unit on roof curb.
6. Verify that the downshot ducts are aligned with the downshot
knockout areas.
7. Re-install horizontal (metal) covers as needed to seal unit. Ensure
opensings are air and watertight.
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.
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 ensure 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
Horizontal Duct Covers
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
1.
Basepan
Downflow
(Vertical)
Supply
Knockout
Fig. 9 – Supply and Return Duct Opening
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 NFPA 70 (NEC)
(latest edition) (in Canada, Canadian Electrical Code CSA C22.1) and
local electrical codes.
A09076
12
WARNING
!
Basepan
Downflow
(Vertical)
Return
Knockout
A09077
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