Installation
WARNING:
Hazardous Pressures! Coil has a nitrogen holding charge. Do not remove seal caps by heating the caps while coil is under pressure. Depress the gauge port valve cores to gradu- ally relieve nitrogen holding charge. Remove valve cores before removing the tubing seal caps. Failure to properly relieve pressure could result in death or serious injury.
1.Remove both seal caps from the indoor unit connection stubs.
CAUTION:
Equipment Damage!
Do not remove the seal caps from refrigerant connections until pre- pared to braze refrigerant lines to the connections. Excessive expo- sure to atmosphere may allow moisture or dirt to contaminate the system, damaging valve seals and causing ice formation in sys- tem components.
2.Turn nitrogen supply on. Nitrogen enters through liquid line gauge port.
WARNING:
Hazard of Explosion and Deadly Gases!
Never solder, braze or weld on refrigerant lines or any unit com- ponents that are above atmo- spheric pressure or where refrigerant may be present. Always remove refrigerant by fol- lowing the guidelines estab- lished by the EPA Federal Clean Air Act or other state or local codes as appropriate. After refrig- erant removal, use dry nitrogen to bring system back to atmospheric pressure before opening system
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for repairs. Mixtures of refriger- ants and air under pressure may become combustible in the pres- ence of an ignition source leading to an explosion. Excessive heat from soldering, brazing or weld- ing with refrigerant vapors present can form highly toxic gases and extremely corrosive acids. Failure to follow all proper safe refrigerant handling prac- tices could result in death or seri- ous injury.
3.Braze the liquid line connections.
4.Open the gauge port on the dis- charge line and then braze the dis- charge line to the connection stub. Nitrogen will bleed out the open gauge port on the discharge line.
5.Shut off nitrogen supply.
Leak Check
After the brazing operation of the out- door and indoor refrigerant lines is complete, check the field brazed con- nections for leaks. Pressurize the sys- tem through the gauge port with dry nitrogen to 200 psi. Use soap bubbles or other
System Evacuation
1.After completion of leak check, replace suction, liquid and dis- charge valve cores, and evacuate the system.
2.Attach appropriate hoses from the manifold gauge to suction and dis- charge line gauge ports.
Note: Unnecessary switching of hoses can be avoided and complete evacua- tion of lines leading to a sealed sys- tem can be accomplished with manifold center hose and connecting branch hose to cylinder of
3.Attach center hose of manifold gauges to the vacuum pump.
4.Evacuate the system to hold a 350 micron vacuum.
5.Close off the valve to the vacuum pump and observe the micron gauge. If gauge pressure rises above 500 microns in one (1) minute, evacuation is incomplete or the system has a leak.
6.If vacuum gauge does not rise above 500 microns in one (1) minute, the evacuation should be complete.
7.With vacuum pump and micron gauge blanked off, open the valve on
8.Close valve on the
9.Leak test the entire system. Using proper procedures and caution, repair any leaks found and repeat the leak test.
Refrigerant Charging Procedure If charging by weight, refer to refriger- ant charges that are provided in Table
3.If additional refrigerant is needed because of length of line, calculate the requirements using Table 4. Charge by weight through the gauge port on the suction line in the indoor unit. When charging is complete, replace the cap on the gauge port.
Insulating and Isolating
Refrigerant Lines
Insulate the entire discharge line with refrigerant piping insulation. Also insulate any portion of the liquid line exposed to temperature extremes. Insulate and isolate liquid and dis- charge lines from each other. Isolate refrigerant lines from the structure and any ductwork.
Note: To prevent possible noise or vibration, be certain to isolate refriger- ant lines from the building.
