When recovering refrigerant from a system, with a burnout, follow a safe procedure due to possible contamination.
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.
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 refrig- erant 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.
DO NOT vent refrigerant to the outdoors.
Avoid getting the refrigerant in the eyes or on the skin.
Contaminated refrigerant must be recovered and returned to the local refrigeration supply house for proper disposition.
TOTAL LINE LENGTH
Units should be installed only with approved system combina- tion (indoor/outdoor) as specified in the Technical Guide.
For systems with total line length exceeding 50 feet, see APPLICATION DATA and work sheet "General Piping Rec- ommendations and Refrigerant Line Length" for vapor and liquid line sizing, calibration of liquid line pressure loss or gain, determination of vapor line velocity, elevation limita- tions, orifice connections, system charging, traps, etc.
Systems with liquid line pressure loss or gain greater than 11 psi must be provided with corrected orifice size as noted in
.APPLICATION DATA.
ORIFICE SELECTION (ON SWEAT FIT COILS)
NOTE: The proper orifice must be installed in the indoor coil liquid line connection prior to the connection of the refrigerant lines.
Coil is under 30 to 35 psig (inert gas) pressure.
Each coil has an orifice installed in the fitting between the liquid line connection and distributor. The orifice is identified on a label next to the liq- uid line connection.
The orifice shipped with the outdoor unit is based on the “most sold” combination, but it may be changed, depending on the capacity and efficiency of the outdoor unit, elevation differences, and/or long total line lengths. An additional ori- fice(s) is shipped with most outdoor units for the most com- monly required replacement combinations. Other sizes must be ordered from Source 1 Parts if required.
See the appropriate Tabular Data Sheet for the correct orifice size and charge adder. If the orifice size matches, nothing fur- ther is required and the refrigerant lines may be connected per the outdoor unit instruction. However, if another orifice should be used, see the coil instruction for details to change the orifice in the coil.
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