Carrier 38YXA - Refrigerant System Preparation; Install Adapter Tube

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.
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 accessory
tubing package or field-supplied refrigerant grade tubing of correct
size and condition. For tubing requirements beyond 50 ft, substan-
tial capacity and performance losses can occur. Follow the
recommendations in the Application Guideline and Service
Manual for Residential Split-System Air Conditioners and Heat
Pumps Using R-410A Refrigerant to minimize losses. Refer to
Table 1 for field tubing diameters. Refer to Table 2 for accessory
requirements.
Refrigerant tubes and indoor coil must be evacuated to 500
microns to minimize contamination and moisture in the system.
OUTDOOR UNIT CONNECTED TO FACTORY-APPROVED
INDOOR UNIT
These outdoor units are carefully evaluated and listed with specific
indoor coils for proper system performance.
IMPORTANT: Do not apply indoor coils which are not factory
approved to these units.
INSTALL ADAPTER TUBE
1. Remove plastic retainer holding outdoor piston in liquid
service valve.
2. Check outdoor piston size with matching number listed on unit
rating plate.
3. Locate plastic bag taped to unit containing adapter tube.
4. Remove teflon washer from bag and install on open end of
liquid service valve. (See Fig. 8.)
5. Remove adapter tube from bag and connect threaded nut to
liquid service valve. Tighten nut finger tight and then with
wrench an additional 1/2 turn (15 ft-lb). DO NOT OVER-
TIGHTEN!.
Fig. 7—Defrost Thermostat Location
A97517
FEEDER TUBE
DEFROST
THERMOSTAT
STUB TUBE
Table 1—Refrigerant Connections and Recommended Liquid and Vapor Tube Diameters (In.)
UNIT
SIZE
CONNECTION DIAMETER TUBE DIAMETER
TUBE DIAMETER
(ALTERNATE)
RST TUBE
DIAMETERS
NOT PERMITTED
Liquid Vapor Liquid Vapor Vapor Vapor
024 3/8 5/8 3/8 5/8 3/4 ACR 3/4
030 3/8 3/4 3/8 3/4 7/8 1-1/8
036 3/8 3/4 3/8 3/4 7/8 1-1/8
042, 048 3/8 7/8 3/8 7/8 7/8 3/4 and 1-1/8
060 3/8 7/8 3/8 1-1/8 7/8 3/4
NOTES:
1. Tube diameters are for lengths up to 50 ft. For tubing lengths greater than 50 ft, consult the Application Guideline and Service Manual for Residential Split-System
Air Conditioners and Heat Pumps Using R-410A Refrigerant.
2. Refrigerant tubes and indoor coils must be evacuated to 500 microns to minimize contamination and moisture in the system.
Table 2—Accessory Usage
ACCESSORY
REQUIRED FOR LOW-AMBIENT
APPLICATIONS
(BELOW 55°F)
REQUIRED FOR LONG-LINE
APPLICATIONS*
(OVER 50 FT)
Crankcase Heater Yes Yes
Evaporator Freeze Thermostat Yes No
Compressor Start Assist—Capacitor and Relay Yes Yes
R-410A Low-Ambient Pressure Switch Yes No
Wind Baffle See Low-Ambient Instructions No
Support Feet Recommended No
R-410A Hard Shutoff TXV Yes† Yes†
R-410A Liquid-Line Solenoid Valve for Heating No
See Long-Line
Application Guideline
* For tubing line sets between 50 and 175 ft, refer to the Application Guideline and Service Manual for Residential Split-System Air Conditioners and Heat Pumps using
R-410A Refrigerant.
† Required for all applications.
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