# Overcharged capillary tube system



## alejo0623 (Mar 25, 2012)

Good day,

Please, can someone explain the behavior of the gas 134A when overcharged in a refrigeration unit ( back bar unit 95 inches, Capillary tube system) how it will affect the saturation point, heat exchange and also can this iced up the evaporator and suction line? 

i have seen that a unit when overcharged it will develop ice at the inlet of the compressor, can this ice climb up to the evaporator and make the evaporator iced up too?

thanks,


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## rmihvacr (Mar 29, 2012)

Yes. When dealing with incremental horsepower refrigeration (under 1 h.p.) it is HIGHLY recommended (and our companies S.O.P.) to weigh in the charge, which is available on data plate. This eliminates the human error when it comes to charging a system. We have found that heat (greater than 105 degrees) causes a slight film to develop inside capillary tube (when P.O.E. is in system)and therefore alters the refrigeration effect (overall I.D. of cap tube becomes smaller). We replace driers and captubes any time we remove refrigerant 134A from a small system. The incurred expense (for us the contractor) is minimal (drier (sporlan CAPT and supco cap tube less than 20$) and has proven to be a benefit for the customer and a good revenue generator for us. Win Win. We replace upwards of 30 a month during the summer (different customers of course).


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## alejo0623 (Mar 25, 2012)

Thank you !!


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## moshei (Jun 21, 2012)

Often a cap tube is branched into several smaller distribution lines that meter refrigerant into different sections of a cooling coil - it's simply a means of efficient distribution to improve coil efficiency, and shouldn't affect the charge quantity.!


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