035-15713-003 REV. A (0500)
Unitary Products Group
5
INSULATION OF VAPOR LINE
Insulate vapor line with 3/8" (or that required by local code)
closed cell insulation.
Slide tubing insulation onto the vapor line so that it is covered
completely from the indoor coil to the outdoor unit. Be sure
that the tubing is capped before sliding on insulation.
It is not necessary to insulate the liquid line.
NOTE:
In areas of extreme temperatures and humidity,
additional insulation may be required to prevent
excessive condensation and loss of capacity.
Do not insulate liquid line and vapor line together. Liquid line
should not be in contact with the vapor line. See Figure 3.
RE-ASSEMBLING, BRAZING AND CLEANING OF
JOINT CONNECTIONS
Remove the Schrader Valve cores from the service valves.
Remove the plugs from the service valve field tubing connec-
tions. Clean the joints to be brazed.
NOTE:
Do not overheat the connection to be brazed as this
can cause improper flow of solder, resulting in a
weak and leaking joint. Never apply heat directly to
face of fitting. Do not heat solder by direct contact
with flame of the torch.
When brazing copper tubing it is very important to preheat
the entire joint before applying the solder. This is done by
sweeping the flame steadily and evenly around the fitting, to
bring both fitting and tubing up to equal temperature before
applying the solder.
Reassemble groups of tubing and fittings, brazing several
joints instead of one joint at a time. This reduces the chance
for error in the alignment of the assembly. Replace Schrader
Valve cores. DO NOT OPEN SERVICE VALVES AT THIS
TIME.
Clean joint connection immediately after brazing with wet rag.
REFRIGERANT LINE SUPPORT
Refrigerant lines should be supported in a way that no dips or
sags occur. We recommend four feet between supports. If
refrigerant lines are to be attached to the home structure,
care should be taken to eliminate the transmission of vibra-
tions. Attach the refrigerant lines to the indoor coil first.
Remove plugs from the indoor coil, then clean joints to be
brazed. Braze refrigerant lines to the indoor coil. Attach
refrigerant lines to the outdoor unit.
CHARGING AND LEAK TESTING
On systems with or without service valves the refrigerant
should be recovered or recycled in accordance with EPA reg-
ulations. In some cases this may require putting piercing
valves on both the high and low sides of the system.
When recovering refrigerant from a system, with a burnout,
follow a safe procedure due to possible contamination.
Contaminated refrigerant must be recovered and returned to
the local refrigeration supply house for proper disposition.
TOTAL LINE LENGTH
For systems with total line length exceeding 50 feet, see
APPLICATION DATA, 690.01-AD1V(1296) and worksheet
690.01-AD1.1V(791) General Piping Recommendations and
“Refrigerant Line Length” for vapor and liquid line sizing, cali-
bration of liquid line pressure loss or gain, determination of
vapor line velocity, elevation limitations, orifice connections,
system charging, traps, etc.
Total line lengths are limited to 75 feet due to the storage
capacity of the accumulator. Systems with total line lengths
over 50 feet must be provided with:
•
Low Voltage Start Kit.
Elevation differences are limited to:
Indoor above outdoor. . . . 50 ft.
Outdoor above indoor . . . 50 ft.
Systems with liquid line pressure loss or gain greater than 11
psi must be provided with corrected orifice size.
FIGURE 3 :
INSULATION OF VAPOR LINE
When using hard solder, an inert gas such as dry
nitrogen must be introduced and permitted to flow
through tubing during brazing to displace air and
prevent oxidation.
DO NOT vent refrigerant to the outdoors.
Avoid getting the refrigerant in the eyes or on the
skin.
