Carrier 38ED - Manual (Page 3)

When 1-1/8 in. tubing is used (38ED036,042,
048,060) braze it to the accessory 1-1/8 x 3/4-in.
suction connection adapter (Carrier Part No.
28VQ900011) or to correctly sized field-supplied
adapter, then make Compatible Fittingconnections.
Isolate interconnecting tubing from framing and
ductwork or where tubing runs thru stud spaces, en­
closed ceilings or pipe chases. Use isolation type
hanger (Fig. 3) since rigid fastening transmits pulsa­
tions to structure creating objectionable sound.
LIQUID LINE
PIPE
HANGER
INSULATION
0" THICK)
Fig. 3 — Refrigerant Line Hangers
Use 1-1/8 in. suction line on 38ED036,042,048
and 060 systems. A capacity reduction results if
Carrier accessory tubing is used on these systems.
(Example: When a 25-ft accessory tubing package is
used on a 38ED048 system, the smaller suction line
results in a 3% capacity reduction.)
Length of interconnecting tubing may necessitate
refrigerant charge adjustment. Follow special re­
quirements described in Start-Up, Refrigerant
Charging, page 6. Do not use less than 10 ft of inter­
connecting tubing. On Carrier accessory tubing
packages, do not cut 5/16-in. or 1 /4-in. liquid line or
7/8-in. suction line. These tubing packages have
swaged ends that if cut, will not fit into refrigerant
line fittings. Bend or coil excess tubing to fit.
Do not use damaged, undersized or contaminated
tubing. Always evacuate or purge evaporator coil
and tubing system. When purging, use field-supplied
refrigerant, not unit holding charge refrigerant.
When making tubing connections, be sure to pro­
vide clearance at unit for electrical connections.
REPLACE THE ACCURATER™ REFRIG­
ERANT CONTROL PISTON IN THE INDOOR
COIL, if required, before connecting refrigerant
lines. See Carrier Cooling System Capacity Optimi­
zation, page 1.
CONNECT REFRIGERANT LINES to fittings on
condensing unit suction and liquid service valves
(Fig. 1). Unit Compatible Fittings permit mechan­
ical (quick connect) or sweat connections.
Models 38ED036,042,048,060 — When using 1-1/8
in. field-supplied suction line, use field-supplied
3 / 4-in. by 1 -1 / 8 in. suction valve connection adapter
(28VQ900011). Sweat connect refrigerant suction
line to 1-1/8 in. end of adapter. Be sure to provide
a heat sink at the service valve to prevent damage
during sweating operation. Connect 3/4-in. end of
adapter to unit suction line Compatible Fitting.
Connect liquid refrigerant line to unit. When a
7/8-in. field-supplied suction line is used, provide
a field-supplied 3/4-in. to 7/8-in. suction line
adapter. (Not necessary if 38LS accessory tubing is
used.)
Mechanical Connection — (Mate one set of eonnec-
tions at a time.)
1. Loosen nut on Compatible Fitting one turn. Do
not remove.
2. Remove plug and be sure O-ring is in the groove
inside the Compatible Fitting.
3. Cut tubing to correct length, deburr and size as
necessary.
4. Insert tube into Compatible Fitting until it
bottoms. Tighten nut until it bottoms on back
coupling flange. Keep tube bottomed in Com­
patible Fitting while tightening nut.
Sweat Connection — (Use refrigerant grade tubing.)
1. Remove locking nut, rubber O-ring and Schrader
core and cap from valve service port.
2. Cut tubing to correct length, deburr and size as
necessary.
3. Insert tube in Compatible Fitting until it bottoms.
Wrap top and bottom of service valves in wet
cloth to prevent damage by heat. Solder with low-
temperature (430 F) silver alloy solder.
4. Replace Schrader core and cap.
5. Evacuate or purge system using field-supplied
refrigerant.
Step 3 — Install Solenoid on Indoor Coil Liquid
Line Fitting — Before making liquid line connec­
tions, install factory-supplied solenoid on indoor
coil liquid line fitting. It is not necessary to flare the
system liquid line if an accessory flare-to-Compatible
Fitting coupler is used (refer to indoor coil installa­
tion instructions. Accessory Flare to Compatible
Coupler).