words are used with the safety-alert symbol. DANGER identifies the most serious hazards which will result in severe personal injury or death. WARNING signifies hazards which could result in per- sonal injury or death. CAUTION is used to identify unsafe practic- es which may result in minor personal injury or product and prop- erty damage. NOTE is used to highlight suggestions which will result in enhanced installation, reliability, or operation.
!WARNING
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 and install lockout tag. There may be more than one disconnect switch. Turn off accessory heater power switch if applicable.
!WARNING
FIRE, EXPLOSION, ELECTRICAL SHOCK AND CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury, death or property damage.
A qualified installer or agency must use only factory-authorized kits or accessories when modifying this product.
!CAUTION
CUT HAZARD
Failure to follow this caution may result in personal injury.
When removing access panels (see Fig. 19) or performing maintenance functions inside your unit, be aware of sharp sheet metal parts and screws. Although special care is taken to reduce sharp edges to a minimum, be extremely careful when handling parts or reaching into the unit.
INTRODUCTION
The 48EZ-A unit (see Fig. 1) is a fully self-contained, combination Category I gas heating/electric heating and cooling unit designed for outdoor installation (See Fig. 2 and 3 for unit dimensions). All unit sizes have return and discharge openings for both horizontal and downflow configurations, and are factory shipped with all downflow duct openings covered. Units may be installed either on a rooftop, or on a cement slab (See Fig. 4 for roof curb dimensions).
Models with an N in the fifth position of the model number are dedicated Low NOx units designed for California installations. These models meet the California maximum oxides of nitrogen (NOx) emissions requirements of 40 nanograms/joule or less as shipped from the factory and must be installed in California Air Quality Management Districts or any other regions in North America where a Low NOx rule exists.
RECEIVING AND INSTALLATION
Step 1 — Check Equipment
IDENTIFY UNIT
The unit model number and serial number are stamped on the unit information plate. Check this information against shipping papers.
INSPECT SHIPMENT
Inspect for shipping damage before removing packaging materials. If unit appears to be damaged or is torn loose from its anchorage, have it examined by transportation inspectors before removal. Forward claim papers directly to transportation company.
Manufacturer is not responsible for any damage incurred in transit. Check all items against shipping list. Immediately notify the nearest equipment distribution office if any item is missing. To prevent loss or damage, leave all parts in original packages until installation.
If the unit is to be mounted on a curb in a downflow application, review Step 9 to determine which method is to be used to remove the downflow panels before rigging and lifting into place. The panel removal process may require the unit to be on the ground.
Step 2 — Provide Unit Support
For hurricane tie downs, contact distributor for details and PE (Professional Engineering) Certificate if required.
ROOF CURB
Install accessory roof curb in accordance with instructions shipped with curb (See Fig. 4). Install insulation, cant strips, roofing, and flashing. Ductwork must be attached to curb.
IMPORTANT: The gasketing of the unit to the roof curb is critical for a water tight seal. Install gasketing material supplied with the roof curb. Improperly applied gasketing also can result in air leaks and poor unit performance.
Curb should be level to within 1/4 in. (6 mm). This is necessary for unit drain to function properly. Refer to accessory roof curb installation instructions for additional information as required.
Installation on older “G” series roof curbs.
Two accessory kits are available to aid in installing a new “G” series unit on an old “G” roof curb.
1.Accessory kit number CPADCURB001A00, (small chassis) and accessory kit number CPADCURB002A00, (large chassis) includes roof curb adapter and gaskets for the perimeter seal and duct openings. No additional modifications to the curb are required when using this kit.
2.An alternative to the adapter curb is to modify the existing curb by removing the outer horizontal flange and use accessory kit number CPGSKTKIT001A00 which includes spacer blocks (for easy alignment to existing curb) and gaskets for the perimeter seal and duct openings. This kit is used when existing curb is modified by removing outer horizontal flange.
!CAUTION
UNIT/STRUCTURAL DAMAGE HAZARD
Failure to follow this caution may result in property damage.
Ensure there is sufficient clearance for saw blade when cutting the outer horizontal flange of the roof curb so there is no damage to the roof or flashing.
SLAB MOUNT
Place the unit on a solid, level concrete pad that is a minimum of 4 in. (102 mm) thick with 2 in. (51 mm) above grade. The slab should be flush on the compressor end of the unit (to allow condensate drain installation) and should extend 2 in. (51 mm) on the three remaining sides of the unit. Do not secure the unit to the slab except when required by local codes.
Step 3 — Field Fabricate Ductwork
Secure all ducts to roof curb and building structure on vertical discharge units. Do not connect ductwork to unit. For horizontal applications, unit is provided with flanges on the horizontal openings. All ductwork should be secured to the flanges. Insulate and weatherproof all external ductwork, joints, and roof openings with counter flashing and mastic in accordance with applicable codes.
