Carrier 38BYC, 38BYG User Manual

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Installation and Start-Up Instructions

NOTE: Read the entire instruction manual before starting the

installation.
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SAFETY CONSIDERATIONS

Improper installation, adjustment, alteration, service, maintenance,
or use can cause explosion, fire, electrical shock, or other
conditions which may cause death, personal injury, or property
damage. Consult a qualified installer, service agency, or your
distributor or branch for information or assistance. The qualified
installer or agency must use factory-authorized kits or accessories
when modifying this product. Refer to the individual instructions
packaged with the kits or accessories when installing.

Follow all safety codes. Wear safety glasses, protective clothing,
and work gloves. Use quenching cloth for brazing operations.
Have fire extinguisher available. Read these instructions thor­oughly and follow all warnings or cautions included in literature
and attached to the unit. Consult local building codes and National
Electrical Code (NEC) for special requirements.

Recognize safety information. This is the safety-alert symbol
When you see this symbol on the unit and in instructions or
manuals, be alert to the potential for personal injury.

Understand the signal words DANGER, WARNING, and CAU­TION. These words are used with the safety-alert symbol. DAN­GER identifies the most serious hazards which willresultinsevere
personal injury or death. WARNING signifies hazards 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.

Before installing, modifying, or servicing system, main elec­trical disconnect switch must be in the OFF position. There
may be more than 1 disconnect switch. Lock out and tag
switch with a suitable warning label. Electrical shock can
cause personal injury or death.

INSTALLATION RECOMMENDATIONS

NOTE: In some cases noise in the living area has been traced to

gas pulsations from improper installation of equipment.

1. Locate unit away from windows, patios, decks, and so forth
where unit operation sounds may disturb customer.

2. Ensure that vapor- and liquid-tubediametersare appropriate to
capacity of unit.

3. Run refrigerant tubes as directly as possible by avoiding
unnecessary turns and bends.

38BYC, 38BYG

12 SEER Split System

Heat Pump

A98525

Fig. 1—Model 38BYG

.

4. Leave some slack between structure and unit to absorb
vibration.

5. When passing refrigerant tubes through the wall, seal opening
with RTV or other pliable silicon based caulk. (See Fig. 2.)

6. Avoid direct tubing contact with water pipes, duct work, floor
joists, wall studs, floors, and walls.

7. Do not suspend refrigerant tubing from joists and studs with a
rigid wire or strap that comes in direct contact with tubing.
(See Fig. 2.)

8. Ensure that tubing insulation is pliable and completely sur­rounds vapor tube.

9. When necessary, use hanger straps which are 1 in. wide and
conform to shape of tubing insulation. (See Fig. 2.)

10. Isolate hanger straps from insulation by using metal sleeves
bent to conform to shape of insulation.

When outdoor unit is connected to factory-approved indoor unit,
outdoor unit contains system refrigerant charge for operation with
indoor unit of the same size when connected by 15 ft of
field-supplied or factory-accessory tubing. For proper unit opera­tion, check refrigerant charge using charging information located
on control box cover.

IMPORTANT: Maximum liquid line size is 3/8-in. O.D. for all
residential applications including long line.

IMPORTANT: Always install a liquid line filter drier on any
system using existing field service line sets and or existing indoor
coil or fan coil units. Always use a filter direr on burnout unit
replacements.

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.

Book 1 4
Tab 5a 5a

PC 101 Catalog No. 533-80078 Printed in U.S.A. Form 38BYC-3SI Pg 1 11-02 Replaces: 38BYC-2SI

Avoid contact between tubing and structureNOTE:

OUTDOOR WALL INDOOR WALL

CAULK

LIQUID TUBE

C

INSULATION

THROUGH THE WALL

HANGER STRAP

(AROUND VAPOR

TUBE ONLY)

1″ MIN.

SUSPENSION

VAPOR TUBE

JOIST

INSULATION

VAPOR TUBE

LIQUID TUBE

A94028

Fig. 2—Connecting Tubing Installation

INSTALLATION

Step 1—Check Equipment and Job Site

UNPACK UNIT
Move to final location. Remove carton, taking care not to damage

unit.
INSPECT EQUIPMENT
File claim with shipping company prior to installation if shipment

is damaged or incomplete. Locate unit rating plate on unit service
panel. It contains information needed to properly install unit.
Check rating plate to be sure unit matches job specifications.

Step 2—Install On A Solid, Level Mounting Pad

If conditions or local codes require the unit be attached to pad,
tiedown bolts should be used and fastened through knockouts
provided in unit base pan. Refer to unit mounting pattern in Fig. 3
to determine base pan size and knockout hole location.

On rooftop applications, mount on level platform or frame. Place
unit above a load bearing wall and isolate unit and tubing set from
structure. Arrange supporting members to adequately support unit
and minimize transmission of vibration to building. Consult local
codes governing rooftop applications.

Roof mounted units exposed to winds above 5 mph may require
wind baffles to achieve adequate defrost. Consult Low Ambient
Guideline for wind baffle construction.

NOTE: Unit must be level to within ± 2° (± 3/8 in./ft) per
compressor manufacturer specifications.

Step 3—Clearance Requirements

When installing, allow sufficient space for airflow clearance,
wiring, refrigerant piping, and service. Allow 30-in. clearance to
service end of unit and 48 in. above unit. For proper airflow, a 6-in.
clearance on 1 side of unit and 12 in. on all remaining sides must
be maintained. Maintain a distance of 24 in. between units.
Position so water, snow, or ice from roof or eaves cannot fall
directly on unit.

3

⁄8″D. (9.53) TIEDOWN

A

KNOCKOUTS (2) PLACES

B

A94199

Dimensions (In.)

UNIT
SIZE

018-024 22-1/2 X 22-1/2 3-11/16 18-1/8 14-3/8
030-060 30 X 30 6-1/2 23-1/2 20

MINIMUM

MOUNTING-PAD

DIMENSIONS

TIEDOWN KNOCKOUT LOCATIONS

ABC

Fig. 3—Mounting Unit to Pad

On rooftop applications, locate unit at least 6 in. above roof
surface.

Step 4—Operating Ambient

The minimum outdoor operating ambient in cooling mode is 55°F,
and the maximum outdoor operating ambient in cooling mode is
125°F. The maximum outdoor operating ambient in heating mode
is 66°F.

Step 5—Elevate Unit

Accumulation of water and ice in base pan may cause
equipment damage.

In areas where prolonged freezing temperatures are encountered,
elevate unit per local climate and code requirements to provide
clearance above estimated snowfall level and ensure adequate
drainage of unit.

Step 6—Remove Indoor AccuRater® Piston and Install
TXV

For proper unit operation and reliability, units must be
installed with field supplied hard shutoff TXV. Do not install
with evaporator coils having capillary tube metering devices
or pistons.

For TXV kit part number and charging instructions, refer to TXV
label in outdoor unit. If indoor unit (fan coil) comes factory
equipped with a bi-flow hard shutoff TXV, no TXV change is
required.

2

If TXV installation is required, remove existing AccuRater® from
indoor coil. Refer to Figs. 4 and 5 and install TXV kit as follows:

1. Install suction tube adapter.

2. Install liquid flare-to-sweat adapter.

3. Connect external equalizer tube to fitting on suction tube
adapter.

4. Position sensing bulb on horizontal portion of suction tube
adapter. Secure using supplied hardware.

5. Insulate bulb after installation. (See Fig. 5.)

6. Leak check all connections.

COIL

SENSING
BULB

EQUALIZER
TUBE

feeder tubes, there is a 3/8-in. O.D. stub tube approximately 2 in.
long. (See Fig. 6.) The defrost thermostat should be located on stub
tube. Note that there is only 1 stub tube used with liquid header,
and on most units it is the bottom circuit.

FEEDER TUBE

STUB TUBE

DEFROST
THERMOSTAT

A97517

Fig. 6—Defrost Thermostat Location

Step 9—Make Piping Connections

THERMOSTATIC
EXPANSION
VALVE

A88382

Fig. 4—Typical TXV Installation

10 O'CLOCK

2 O'CLOCK

SENSING BULB

STRAP

SUCTION TUBE

4 O'CLOCK

7⁄

IN. OD

8

A81032

7

⁄

IN. OD & SMALLER

8

8 O'CLOCK

LARGER THAN

Fig. 5—Positioning of Sensing Bulb

Step 7—Check Outdoor AccuRater® Piston

Check outdoor unit piston. Remove retainer on liquid service valve
and check piston size with matching number listed on outdoor unit
rating plate.

Step 8—Check Defrost Thermostat

Check defrost thermostat to ensure it is properly located and
securely attached. There is a liquid header with a brass distributor
and feeder tube going into outdoor coil. At the end of 1 of the

Relieve pressure and recover all refrigerant before system
repair or final unit disposal to avoid personal injury or death.
Use all service ports and open all flow control devices,
including solenoid valves.

If ANY refrigerant tubing is buried, provide a 6 in. vertical
rise at service valve. Refrigerant tubing lengths up to 36 in.
may be buried without further special consideration. For
lengths longer than 36 in., refer to Application Guideline and
Service Manual — Residential Split System Air Conditioners
and Heat Pumps.

To prevent damage to unit or service valves observe the
following:

•Use a brazing shield.

•Wrap service valves with wet cloth or use a heat-sink
material.

Outdoor units may be connected to indoor section using accessory­tubing package or field-supplied refrigerant grade tubing of correct
size and condition. For tubing requirements beyond 50 ft, substan­tial capacity and performance losses can occur. Following the
recommendations in the Residential Split System Long-Line
Application Guideline will reduce these losses. Refer to Table 1
for field tubing equivalent line length. Refer to Table 2 for
accessory requirements.

For buried line applications greater than 36 in., refer to Table 2 and
Residential Split System Buried Line Application Guideline.
Buried line applications may not exceed 100 ft.

If refrigerant tubes or indoor coil are exposed to atmosphere, they
must be evacuated to 500 microns to eliminate contamination and
moisture in the system.

3