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12-6. In Case Refrigerant is Leaking
(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 utiliz-
ing substitution with nitrogen (N2) in the refrigerant
circuit of the unit. Leave ends of tubes open during
welding.
(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 valve-installed vacuum pump
so
that even if power is cut off in the middle of evacuation
of air due to a power interruption, the valve will prevent
the pump oil from flowing back.
● 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:
Standard time for evacuation
(6) Recharging
● Recharge unit in the same manner explained on the
previous page “(5) Recharging.”
