3  Piping work and 
refrigerant charge
92
SMGB0077 rev.0 - 01/2013
3.1  Refrigerant pipe selection
3.1.1  Refrigerant pipe selection
N O T E
Consult the corresponding Technical Catalogue for outdoor units from the UTOPIA or SET FREE Series.
 
  
Pipe size selection
Select the pipe size in line with the following instructions:
1  Between the outdoor unit and the branch pipe (multikit): select the same pipe connection size as for the outdoor unit.
2  Between the branch pipe (multikit) and the indoor unit: select the same pipe connection size as for the indoor unit.
C A U T I O N
•  Do  not use  refrigerant  pipe sizes  other  than  those indicated  in  the corresponding  Technical Catalogue  for 
outdoor units. The diameter of the refrigerant pipes depends directly on the power of the outdoor unit. 
•  If larger diameter refrigerant pipes are used, the circuit lubrication oil tends to separate from the gas carrying 
it. The compressor will be seriously damaged due to a lack of lubrication.
•  If smaller diameter refrigerant pipes are used, the gas or liquid refrigerant will have serious difculties in
circulating. System performance will be affected. The compressor will run under more severe conditions than 
foreseen and will be damaged in a short space of time.
 
  
Multikit or distributor selection
N O T E
•  Pipe  connection  sizes  on  outdoor units,  indoor  units  and  the  multikit  or  distributor  vary depending  on  the 
system. Consult the Service Manual for the UTOPIA or SET FREE Series.
•  Thesizesoftheindoorandoutdoorunitsaredifferent.Adjusttheareadapter(accessory)totheindoorpipe
connection.