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38GNA
User Manual
8 pgs104.29 Kb0
Installation And Start-up Instructions Manual
8 pgs506.73 Kb0
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Carrier 38GNA User Manual

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HEATING & COOUNG

38GNA

Air Conditioning Unit

instaliation and Start-up instructions

NOTE: Read the entire instruction manual before starting the
installation.

SAFETY CONSIDERATIONS

Improper installation, adjustment, alteration, service, maintenance, or use can cause explosion, fire, electrical shock or other condi tions which may cause 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 pack aged with the kits or accessories when installing.
Follow all safety codes. Wear safety glasses and work gloves. Use quenching cloth for brazing operations. Have fire extinguisher available. Read these instructions thoroughly and follow all warnings or cautions attached to the unit. Consult local building codes and National Electrical Code (NEC) for special require ments.
It is important to recognize safety information. This is the safety­alert symbol /îy . When you see this symbol on the unit and in instructions or manuals, be alert to the potential for personal injury.
Understand the signal word DANGER, WARNING, or CAU TION. These words are used with the safety-alert symbol. DAN GER identifies the most serious hazards which will result in severe personal injury or death. WARNING signifies hazards that 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.
The 024 size is equipped with a time-delay device which prevents restart within 5 minutes of power interruption.
Compressor motor is equipped with an internal protector. Exces sive current or temperature causes protector to open which gives indication of an open circuit in motor winding. Sufficient time should be allowed for overload to reset before assuming compres sor has an open winding.
Compressor motor is designed to start under low-load conditions only. Make sure system pressures have equalized before attempt ing to start unit. Equalization takes approximately 3 minutes. Owner should be informed not to short-cycle unit with thermostat as this causes compressor to trip out on overload.
Each unit is shipped with refrigerant charge adequate for use with matching coils and refrigerant tubing kits. Charge is adequate for systems using 25 ft of interconnecting tubing. See unit rating plate for charge quantity. See Refrigerant Charging section and Table 2 for adjustment requirements.

A WARNING

Relieve all pressure before refrigerant 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.

A CAUTION

Do not vent refrigerant to atmosphere. Recover during system repair or final unit disposal.
A WARNING
Before installing or servicing system, always turn off main power to system. There may be more than 1 disconnect switch. Turn off accessory heater power if applicable. Elec trical shock can cause personal injury or death.
Intake and discharge are on front of the unit. A minimum service access distance of 30 in. behind unit must be provided.
NOTE: Refer to unit rating plate for ratings. '
This condensing unit is designed for use with evaporator coils or fan coils equipped with capillary tube or piston-type refrigerant control device. It may also be used with evaporators which have expansion valves that equalize pressure during the off cycle or hard shut-off expansion valves. The 018 size with hard shut-off expansion valve requires a hard start kit.

BEFORE INSTALLATION

Check power supply: voltage, frequency and phase must corre spond with data on unit rating plate. Power supply must be able to handle the additional load imposed by this equipment.
The 38GNA does not have a transformer. Therefore, the furnace transformer (or another source) must be used as a low-voltage supply. Transformer must have an additional capacity of 15 va above the requirement of furnace or air handler.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obiigations.
Book] 1 I 4 PC 101 Catalog No. 563-712 Printed in U.S.A. Form 38GNA-2SI Pg 1 11-92 Replaces: 38GNA-1 SI
Tab |3a|2a

GENERAL

NOTE: Check indoor coil piston to see if it matches the required
piston shown on unit rating plate. If it does not match, replace indoor coil piston with piston shipped with this unit. The piston shipped with outdoor unit is correct for any approved indoor coil combination.
Table 1—Installation Data (In.)
38GNA
Through-the-Wall
Clearance Dim.
Air Clearance
Concrete Mounting
Pad Dim.
Service Clearance*
’Unit is serviced through rear access panel. Therefore, unit can be installed with 0-in. end clearance.
Sides
Back
018 024
26-1/2 X 29
36
27 X 17 X 5
0
30

INSTALLATION

Install condensing unit either through-the-wall, outdoors on a slab or on the roof. When installing, allow sufficient space for airflow clearance, wiring, refrigerant piping and servicing. Consult local building codes and National Electrical Code (NEC) for special installation requirements. See Fig. 1, 2 and 3 and Table 1 for detailed installation data.
AIR OUT
Fig. 1—Dimensions and Connections
7/8 DIA HOLE & 1-3/32 DIA K.O.
POWER INLET
A75135
Fig. 2—Roughing-ln Supporting Frame

Step 1—Make Opening in Wall

Make an opening approximately 26-1/2 x 29 in. in a wall as close to the cooling unit as possible. Build a frame to support the condensing unit. (See Fig. 2.)
1. Insert condensing unit with frame into the wall opening.
2. Extend unit approximately 1 in. beyond outside (finished) wall and tilt to the outside to allow rainwater to drain off. (See Fig.
3.)
3. Fasten unit to frame with metal straps.
4. Use flashing under unit and caulk all edges to provide weathertight seal. (See Fig. 3.)
(M>

Step 2—Make Piping Connections

SELECT CORRECT LIQUID AND SUCTION LINE LENGTHS/DIAMETERS - Refer to Table 2.
INSTALL REFRIGERANT LINES — The condensing unit is fully charged at the factory. Be sure both service valves are front seated (turned clockwise) to avoid loss of charge. Do not remove
refrigerant line connection seals from condensing unit, matching coil, or refrigerant tubing until ready to make actual connection at
point of seal.
Table 2—Tubing Data
REFRIGERANT LINE LENGTH
UNIT SIZE
018, 024
1. Maximum vertical separation for evaporator over condensing unit is 50 ft.
2. Over 50 ft of vertical separation, the condensing unit must be located above
the evaporator. For requirements beyond 50 ft, obtain information from distributor or consult Long-Line Application Guideline.
3. Charge adjustment is required when using more than 25 ft of tubing. See
Refrigerant Charging information on unit rating plate.
4. Do not use larger than 3/4-in. suction line.
10 to 50 ft
Suction
5/8 3/8
Diameter (In.)
Liquid Suction
If accessory tubing package or evaporator coil has been open for more than 5 minutes, evacuate evaporator coil and tubing system. Always evacuate if field-supplied tubing is used. See Evacuation section.
Ensure field-supplied tubing is of refrigerant grade. Insulate the suction line with insulation that has an adequate vapor barrier. Evacuate tubing.
1. Run refrigerant lines as directly as possible, avoiding any unnecessary turns and bends.
2. Tape the liquid line to the top of the insulated suction line for support.
3. Suspend the refrigerant lines so they do not damage the insulation on the suction line and do not transmit vibration to the structure.
4. If the refrigerant lines are too long, the excess may be cut off.
5. Connect tubing to the condensing unit. The refrigerant tubing and evaporator coil should be leak tested upon completion.
When making piping connections, be sure to provide clearance at unit for electrical connection.
Connect suction and liquid refrigerant lines to condensing unit. (See Fig. 1.) Make suction line connection first.
Two grommets are provided to seal the gap between refrigerant lines and unit casing. Cut small grommet, slip it over liquid line and push it into casing opening. Gap around suction line is sealed in same manner except that suction line insulation must be cut and pushed back before grommet can be slipped into place. (See Fig.
4.) FIELD TUBING CONNECTIONS - All models are equipped
with 3/8-in. liquid and 5/8-in. suction back seated service valves with mechanical flare field connections. Factory-supplied 3/8-in. to 3/8- in. and 5/8-in. to 5/8-in. flare-to-sweat adaptor tubes are provided. Field-supplied couplings are required for tubing pack ages exceeding 50-ft long-line applications.
51 to 100 ft
3/4
Liquid
3/8
Step 3—^Test Unit
LEAK TESTING — No installation is complete until all field and factory joints have been checked for leaks.
1. Remove valve stem caps from both service valves and check to be sure valves are front seated (turned clockwise). Remove service port caps.
2. Attach gage manifold to service ports of service valves and purge hoses.
3. Pressurize evaporator coil and interconnecting refrigerant tubing with vapor from an external refrigerant cylinder of R-22 until the system and cylinder pressure are equalized.
NOTE: NEVER USE A UNIT CHARGE FOR LEAK TEST
ING.
4. Leak test with an electronic detector, a halide torch, or a liquid soap solution.
5. Recover refrigerant and repair any leaks.
6. If system is free of leaks, prepare unit for operation.
EVACUATION
1. Connect evacuation equipment to system gage manifold.
2. Evacuate system following appropriate steps for type of evacuation equipment used.
3. Pressurize system with refrigerant to 10 psig and open (turn counter-clockwise) both service valves.
4. Remove gage manifold. Replace valve stem and service port caps on both service valves.
Step 4—Make Electrical Connection
Field wiring must comply with local and national fire, safety and electrical codes. Voltage to unit must be within range of 253v to
187v. Refer to nameplate for other electrical data. Contact local
power company for correction of improper line voltage.

A WARNING

According to NEC, ANSI/NFPA 70, and local codes, the cabinet must have an uninterrupted or unbroken ground, to minimize personal injury if an electrical fault should occur. The ground may consist of electrical wire or metal conduit when installed in accordance with existing electrical codes. Failure to follow this warning could result in an electric shock, fire, or death.
See unit’s rating plate for recommended fuse size. When making electrical connections, provide clearance at unit for refrigerant piping connections.
BRANCH CIRCUIT DISCONNECT - Install a branch circuit disconnect per NEC of adequate size to handle unit starting current. Locate disconnect within sight from and readily accessible from unit, per Section 440-14 of the NEC.
LINE POWER LEADS Extend leads from disconnect per NEC into unit through hole
provided in service panel. (See Fig. 1.) Connect ground lead to ground lug in control box for safety. Connect line power leads to contactor screw terminals LI and L2. (See Fig. 5 or 6.) Contactor terminals are approved for use with copper field wiring.
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