Introduction; Receiving And Installation; Check Equipment; Identify Unit - Carrier 50HX Installation, Start-Up, And Operating Instructions Manual

Before performing service or maintenance operations on
system, turn off power to unit. Turn off accessory heater
power switch, if applicable. Electrical shock can cause
personal injury.
Recognize safety information. This is the safety-alert symbol
When you see this symbol in instructions or manuals, be alert to
the potential for personal injury.
Understand the signal words DANGER, WARNING, CAUTION,
and NOTE. These 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 a hazard
which could result in personal injury or death. CAUTION is used
to identify unsafe practices which would result in minor personal
injury or product and property damage. NOTE is used to highlight
suggestions which will result in enhanced installation, reliability,
or operation.
These instructions cover minimum requirements and conform to
existing national standards and safety codes. In some instances,
these instructions exceed certain local codes and ordinances,
especially those that may not have kept up with changing residen-
tial construction practices. We require these instructions as a
minimum for a safe installation.

INTRODUCTION

The 50HX units (see Fig. 1) are fully self-contained, and designed
for outdoor installation. See Figs. 2–5 for unit dimensions. All
units are shipped in a horizontal-discharge configuration for
installation on a ground-level slab. All units can be converted to
down-flow discharge configurations for rooftop applications. (See
Fig. 6 for roof curb dimensions.)

RECEIVING AND INSTALLATION

Step 1—Check Equipment

IDENTIFY UNIT

The unit model number and serial number are stamped on the unit
identification plate. Check this information against shipping pa-
pers.

INSPECT SHIPMENT

Inspect for shipping damage while unit is still on shipping pallet.
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. Manu-
facturer is not responsible for any damage incurred in transit.
Check all items against shipping list. Immediately notify the
nearest distributor if any item is missing. To prevent loss or
damage, leave all parts in original packages until installation.
Step 2—Provide Unit Support
ROOF CURB & SLAB MOUNT
ROOF CURB - Install accessory roof curb in accordance with
instructions shipped with curb (See Fig. 6). 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 watertight 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 (See Fig. 8). This is necessary
for unit drain to function properly. Refer to accessory roof curb
installation instructions for additional information as required.
SLAB MOUNT - Place the unit on a solid, level concrete pad that
is a minimum of 4 in. thick with 2 in. above grade (See Fig. 10).
The slab should extend approximately 2 in. beyond the casing on
all 4 sides of the unit. Install a 6-in. gravel apron in front of
outdoor coil-air inlet to prevent obstruction of airflow by grass or
shrubs. Do not secure the unit to the slab except when required by
local codes.
Step 3—Provide Clearances
The required minimum service clearances are shown in Fig. 2-5.
. Adequate ventilation and outdoor air must be provided. The
outdoor fan pushes air through the outdoor coil and discharges it
through the louvers on the top cover, the decorative grille, and the
compressor access panel. Be sure that the fan discharge does not
recirculate to the outdoor coil. Do not locate the unit in either a
corner or under an overhead obstruction. The minimum clearance
under a partial overhang (such as a normal house overhang) is 48
in. above the unit top. The maximum horizontal extension of a
partial overhang must not exceed 48 in.
IMPORTANT: Do not restrict outdoor airflow. An air restriction
at either the outdoor-air inlet or the fan discharge may be
detrimental to compressor life.
Do not place the unit where water, ice, or snow from an overhang
or roof will damage or flood the unit. Do not install the unit on
carpeting or other combustible materials. Slab-mounted units
should be at least 4 in. above the highest expected water and runoff
levels. Do not use unit if it has been under water.
Step 4—Select and Install Ductwork
The design and installation of the duct system must be in
accordance with the standards of the NFPA (National Fire Protec-
tion Association) for installation of nonresidence-type air condi-
tioning and ventilating systems, NFPA90A or residence type,
NFPA90B; and/or local codes and residence-type, NFPA90B;
and/or local codes and ordinances. Select and size ductwork,
supply-air registers and return-air grilles according to ASHRAE
(American Society of Heating, Refrigeration, and Air Condition-
ing Engineers) recommendations. The unit has duct flanges on the
supply- and return-air openings on the side of the unit. See Fig. 2-5
for connection sizes and locations. When designing and installing
ductwork, consider the following:
When connecting ductwork to units, do not drill deeper than
1/2–in. in shaded area shown or coil may be damaged.
1. All units should 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.
2. Avoid abrupt duct size increases and reductions. Abrupt
change in duct size adversely affects air performance.
IMPORTANT: Use flexible connectors between ductwork and
unit to prevent transmission of vibration. Use suitable gaskets to
ensure weathertight and airtight seal. When electric heat is
installed, use fireproof canvas (or similar heat resistant material)
connector between ductwork and unit discharge connection. If
flexible duct is used, insert a sheet metal sleeve inside duct. Heat
resistant duct connector (or sheet metal sleeve) should extend
24-in. from electric heater element.
3. Size ductwork for cooling air quantity (cfm). The minimum
air quantity for proper electric heater operation is listed in
Table 2. Heater limit switches may trip at air quantities below
those recommended.
NOTE: A 90-degree elbow must be provided in the supply
ductwork to comply with UL (Underwriters' Laboratories) codes
for use with electric heat.
4. Insulate and weatherproof all external ductwork. Insulate and
cover with a vapor barrier all ductwork passing through
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