Johnson Controls 13 SEER Piping Connections, OIL Trapping, Precautions During Line Installation

347337-UIM-A-0408

PIPING CONNECTIONS

The outdoor condensing unit must be connected to the indoor evapora- tor coil using field supplied refrigerant grade (ACR) copper tubing that is internally clean and dry. Units should be installed only with the tubing sizes for approved system combinations as specified in tabular data sheet. The charge given is applicable for total tubing lengths up to 15 feet. See Application Data Part Number 036-61920-000 for installing tubing of longer lengths and elevation differences.

NOTE: Using a larger than specified line size could result in oil return problems. Using too small a line will result in loss of capacity and other problems caused by insufficient refrigerant flow. Slope horizontal vapor lines at least 1" every 20 feet toward the out- door unit to facilitate proper oil return.

OIL TRAPPING

When the outdoor unit is above the indoor coil, oil trapping is necessary. An oil trap should be provided for every 20 ft. of rise. See Figure 2.

	OUTDOOR COIL
	10 In.
	20 Ft.
INDOOR	6 In.
COIL	20 Ft.

FIGURE 2: Oil Trap

PRECAUTIONS DURING LINE INSTALLATION

1.Install the lines with as few bends as possible. Care must be taken not to damage the couplings or kink the tubing. Use clean hard drawn copper tubing where no appreciable amount of bending around obstruction is necessary. If soft copper must be used, care must be taken to avoid sharp bends which may cause a restriction.

2.The lines should be installed so that they will not obstruct service access to the coil, air handling system, or filter.

3.Care must also be taken to isolate the refrigerant lines to minimize noise transmission from the equipment to the structure.

4.The vapor line must be insulated with a minimum of 1/2" foam rub- ber insulation (Armaflex or equivalent). Liquid lines that will be exposed to direct sunlight, high temperatures, or excessive humid- ity must also be insulated.

5.Tape and suspend the refrigerant lines as shown. DO NOT allow tube metal-to-metal contact. See Figure 3.

6.Use PVC piping as a conduit for all underground installations as shown in Figure 4. Buried lines should be kept as short as possible to minimize the build up of liquid refrigerant in the vapor line during long periods of shutdown

7.Pack fiberglass insulation and a sealing material such as perma- gum around refrigerant lines where they penetrate a wall to reduce vibration and to retain some flexibility.

8.For systems with total line length exceeding 50 ft., see APPLICA- TION DATA and worksheet "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.

Sheet Metal Hanger

Liquid

Line

Incorrect

Tape

Correct

Insulated Vapor Line

FIGURE 3: Installation of Vapor Line

TO INDOOR COIL		TO OUTDOOR UNIT
Liquid Line	Insulated
		Cap
	Vapor Line
PVC
Conduit

FIGURE 4: Underground Installation

PRECAUTIONS DURING BRAZING OF LINES

All outdoor unit and evaporator coil connections are copper-to-copper and should be brazed with a phosphorous-copper alloy material such as Silfos-5 or equivalent. DO NOT use soft solder. The outdoor units have reusable service valves on both the liquid and vapor connections. The total system refrigerant charge is retained within the outdoor unit during shipping and installation. The reusable service valves are pro- vided to evacuate and charge per this instruction.

Serious service problems can be avoided by taking adequate precau- tions to assure an internally clean and dry system.

Dry nitrogen should always be supplied through the tubing while it is being brazed, because the temperature required is high enough to cause oxidation of the copper unless an inert atmosphere is pro- vided. The flow of dry nitrogen should continue until the joint has cooled. Always use a pressure regulator and safety valve to insure that only low pressure dry nitrogen is introduced into the tubing. Only a small flow is necessary to displace air and prevent oxidation.

PRECAUTIONS DURING BRAZING SERVICE VALVE

Precautions should be taken to prevent heat damage to service valve by wrapping a wet rag around it as shown in Figure 5. Also, protect all painted surfaces, insulation, and plastic base during brazing. After braz- ing, cool joint with wet rag.

This is not a backseating valve. The service access port has a valve core. Opening or closing valve does not close service access port.

If the valve stem is backed out past the chamfered retaining wall, the O-ring can be damaged causing leakage or system pressure could force the valve stem out of the valve body possibly causing personal injury.

Valve can be opened by removing the plunger cap and fully inserting a hex wrench into the stem and backing out counter-clockwise until valve stem just touches the chamfered retaining wall.

Johnson Controls Unitary Products 3