Hitachi RAS-18FSXNS2E - Connection Kit Selection; Pipe Size Selection

13
PMML0628 rev.0 - 05/2023
3
CONNECTION KIT SELECTION
PIPING WORK AND REFRIGERANT CHARGE
3.1 Connecon kit selecon
! CAUTION
When brazing pipes, always protect the surrounding elements of the working area in order to avoid
damage due to the high temperature of the ame.
The oponal piping connecon kit is required for the combinaon unit.
Operaon mode Outdoor unit
Number of
outdoor units
Connecon kit
Heat pump system
air365 Max
26 - 48 2 MC-21AN1
50 - 54 3 MC-30AN1
56 - 72 3 MC-NP31SA
74 - 96 4 MC-NP40SA
air365
Max Pro
20 - 24 2 MC-20AN1
26 - 36 2 MC-21AN1
38 - 54 3 MC-30AN1
Heat recovery system
air365
Max
26 - 48 2 MC-21XN1
50 - 54 3 MC-30XN1
air365
Max Pro
20 - 24 2 MC-20XN1
26 - 36 2 MC-21XN1
38 - 54 3 MC-30XN1
3.2 Pipe size selecon
Select the pipe size in line with the following instrucons:
Between the outdoor unit and the branch pipe (mul-kit): select the same pipe connecon size as
for the outdoor unit.
Between the branch pipe (mul-kit) and the indoor unit: select the same pipe connecon size as
for the indoor unit.
! CAUTION
• Do not use refrigerant pipe sizes other than those indicated in the technical informaon. The
diameter of the refrigerant pipes depends directly on the power of the outdoor unit.
• If larger diameter refrigerant pipes are used, the circuit lubricaon oil tends to separate from
the gas carrying it. The compressor will be seriously damaged due to a lack of lubricaon.
• If smaller diameter refrigerant pipes are used, the gas or liquid refrigerant will have serious
dicules in circulang. System performance will be aected. The compressor will run under
more severe condions than foreseen and will be damaged in a short space of me.
• The copper pipe used in the refrigeraon installaons is dierent to the copper pipe used in
installaons carrying domesc or heang water.