Carrier 42LUVH055N Service Manual

116.4 Air purging of the piping and indoor unitRequired tools:Hexagonal wrench; adjustable wrench; torque wrenches, wrench to hold the joints and gas leak detector.Note:The air in the indoor unit and in the piping must be purged. If air remains in the refrigeration piping, it will affect thecompressor, reduce the cooling capacity, and could lead to a malfunction of unit.Be sure, using a torque wrench to tighten the service port cap (after using the service port), so that it prevents the gasleakage from the refrigeration cycle.Procedure1. Recheck the piping connections.2. Open the valve stem of the 2-way valvecounterclockwise approximately 90’, wait 10 seconds,and then set it to closed position.Be sure to use a hexagonal wrench to operate the valvestem.3. Check for gas leakage.Check the flare connection for gas leakage4. Purge the air from the system.Set the 2-way valve to the open position and remove thecap from the 3-way valve’s service port.Using the hexagonal wrench to press the valve core pin,discharge for three seconds and then wait for one minute.5. Use torque wrench to tighten the service port capto a torque of 1.8 kgf.m. (18N.m)6. Set the 3-way valve to the opened position.7. Mounted the valve stem nuts to the 2-way and3-way valves.8. Check for gas leakage.At this time, especially check for gas leakage from the2-way and 3-way stem nuts, and from the service port.Caution:If gas leakage is discovered in step (3) above, take thefollowing measures.If the leaks stop when the piping connections aretightened further, continue working from step (4).If the gas leaks do not stop when the connections areretightened, repair the location of the leak, discharge all ofthe gas through the service port, and then recharge withthe specified amount of gas from a gas cylinder.