9-6. In Case Refrigerant is Leaking
CAUTION
Never attempt to charge additional refrigerant when refrigerant has been leaking from the unit. Follow the procedure described below to locate points of leaks and carry out repairs, then recharge the refrigerant.
(1) Detecting Leaks
Use the detector for R410A to locate refrigerant leak points.
(2) Recovering refrigerant
Never release the gas to the atmosphere; recover residual refrigerant using the refrigerant recovery unit for R410A, instead.
Do not reuse the recovered refrigerant because its composition will have been altered.
(3) Welding leaking points
Confirm again that no residual refrigerant exists in the unit before starting welding.
Weld securely using flux and wax for R410A.
Prevent oxide film from forming inside the tubes utilizing substitution with nitrogen (N2) in the refrigerant circuit of the unit. Leave ends of tubes open during welding.
(1) Detect leaks
OK
(2)Recover refrigerant
OK
(3)Weld leaking points
OK
(4) Checking for sealing
Use nitrogen gas for the pressurized gas, and never use a refrigerant other than R410A. Also do not use oxygen or any flammable gas.
(5) Evacuation
Use a solenoid
The equipment may be damaged if moisture remains in the tubing, thus carry out the evacuation thoroughly.
When using a vacuum pump with exhaust air volume more than 25L/min. and ultimate vacuum pressure rate of 0.05Torr.
(4)Check for sealing
OK
(5)Evacuation
OK
(6) Recharge
Standard time for evacuation
Length of tubing | Less than 10 meters | More than 10 meters |
Evacuation time | More than 10 minutes | More than 15 minutes |
(6) Recharging
Recharge unit in the same manner explained on the previous page "(5) Recharging."
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