Assessments - 3, GPA: 4
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Facilidade de uso
Tighten to 20 - 30 ft. lbs. Use backup wrench on all wrench flats. Overtightening will crush the teflon seal and may cause a leak. 506469-01 Issue 1008 Page 9 of 24 3. Connect the external equalizer line to the equalizer port on the suction line and tighten to 8 ft.lbs. 4. Strap the superheat sensing bulb to the suction header. If installing an expansion valve on an indoor coil that previously used a fixed orifice, be sure to remove the existing fixed orifice. Failure to remove a fixed orifice when installing an expansion valve to the indoor coil will result in improper operation and damage to the system. Manifold Gauge Set Manifold guage sets used with systems charged with R410A refrigerant must be capable of handling the higher system operating pressures. The gauges should be rated for use with pressures 1 - 800 on the high side and a low side of 30” vacuum to 250 psi with dampened speed to 500 psi. Gauge hoses must be rated for use at up to 800 psi of pressure with a 4000 psi burst rating. Liquid and Suction Line Service Valves The liquid line and suction line service valves (See Figure 11) and service ports are used for leak teating, evacuation, charging, and checking charge. Each valve is equipped with a service port which has a factory-installed Schrader valve. A service port cap protects the Schrader valve from contamination and serves as the primary leak seal. To Access the Schrader Port: 1. Remove the service port cap with an adjustable wrench. 2. Connect gauge to the service port. 3. When testing is completed, replace service port cap. Tighten finger tight, then an additional 1/6 turn. To Open Liquid or Suction Line Service Valve: Remove stem cap with an adjustable wrench. Use service wrench with a hex-head extension to back the stem out counterclockwise as far as it will go. Use a 3/16” hex head extension for liquid line service valves and a 5/ 16” extension for suction line service valves. Replace the stem cap. Tighten finger tight, then tighten an additional 1/6 turn. To Close Liquid or Suction Line Service Valve: 1. Remove the stem cap with an adjustable wrench. 2. Use a service wrench with a hex-head extension to turn the stem clockwise to seat the valve. Tighten firmly. 3. Replace the stem cap. Tighten finger tight, then tighten an additional 1/6 turn. Suction Line (Ball Type) Service Valve Suction line (ball type) service valves function the same way as the other valves; the difference is in the construction (See Figure 12). The ball valve is equipped with a service port with a factory- installed Schrader valve. A service port cap protects the Schrader valve from contamination and serves as the primary seal. Leak Testing After the line set has been connected to the indoor and outdoor units, the line set connections and indoor unit must be checked for leaks. Figure 11 506469-01 Issue 1008 Page 10 of 24 Figure 12 WARNING Refrigerant can be harmful if inhaled. Refrigerant must always be used and recovered responsibly. Incorrect or irresponsible use of refrigerant can result in personal injury or death. WARNING Never use oxygen to pressurize refrigeration or air conditioning systems. Oxygen will explode on contact with oil and could cause personal injury or death. Using an Electronic Leak Detector 1. Connect the high pressure hose of the manifold gauge set to the suction valve service port. (Normally the high pressure hose is connected to the liquid line port; however, connecting it to the suction ports helps to protect the manifold gauge set from damage caused by high pressure.) 2. With both manifold valves closed, connect the cylinder of R410A refrigerant. Open the valve on the R410A cylinder (vapor only). 3. Open the high pressure side of the manifold to allow R410A into the line set and indoor unit. Weigh in a trace amount of R410A. (A trace amount is a maximum of 2 oz. of refrigerant or 3 lbs. pressure.) Close the valve on the R410A cylinder and the valve on the high pressure side of the manifold gauge set. Disconnect the R410A cylinder. 4. Connect a cylinder of nitrogen with a pressure regulating valve to the center port of the manifold gauge set. When using high pressure gas such as nitrogen for this purpose, be sure to use a regulator that can control the pressure down to 1 or 2 psig. 5. Adjust nitrogen pressure to 150 psig. Open the valve on the high side of the manifold gauge set to pressurize the line set and the indoor coil. 6. After a short period of time, open a refrigerant port to make sure that an adequate amount of refrigerant has been added for detection (refrigerant requirements will vary with lenths). Check all joints for leaks. Purge nitrogen and R410A mixture. Correct any leaks and rechecks. Evacuation Evacuating the system of noncondensables is critical for proper operation of the unit. Noncondensables are defined as any gas that will not condense under temperatures and pressures present during operation of an air conditioning system. Noncondensables and water vapor combi...