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07.16 207477 Rev.108
ROOF TOP UNITS
– AXIAL FAN
RMXCA/RMXCBA
REFRIGERANT CHARGE
• If it is necessary to add or recuperate refrigerant 410A always do it in its LIQUID state. Charging refrigerant in gas or
vapor form will result in wrong mixture conditions.
• Due to R410A’s high pressure and quick evaporation, the refrigerant cannot stay in a liquid state inside the charge
cylinder when this method is used. It generates bubbles on the window’s scale and makes it difficult to take a reading.
(Conventional charge cylinders for R22 cannot be used because of the difference in resistance to pressure, scale
grading, size of the connections, and so on).
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•Immediately repair all refrigerant leaks.
• Never overload the system.
•Never use compressor as vacuum pump.
•If symptoms of loss of refrigerant appear during operation, it’s necessary to carry out a leak test. Leak detectors usually
employed with CFC and HCFC cannot be used with R410A, due to chlorine in its composition. A leak detector for R134a
may be used but the sensibility of the detector will be lower (when sensibility is 1 for R134a, it falls to 0.6 for R410A).
•To find small leaks, a detector for HCF shall be used. Sensibility for R410A is approximately 23 grams per year.
•If a gas leak is found, it will be necessary to remove and completely recover the refrigerant charge. Pressurize the
system with dry nitrogen. If no leakage is detected, then do the vacuum and charge again with refrigerant.
Never use oxygen to pressurize system or purge lines for leak test. Oxygen reacts
violently with oil, which can cause an explosion resulting in damage, personal injury
or death.
If it is necessary to perform a brazing operation, first fill the circuit with dry
nitrogen. Burning of R410A results in toxic gas emission.
ATTENTION
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ATTENTION
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