Hitachi Set Free mini-HNRQ1 Series, Service Manual

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INSTALLATION
3.3 Refrigerant Piping Size
Example of connection: connection of 4 indoor units.
Table 3.1 Piping Size of Main Pipe
Model
Stop Valve
(mm)
Pipe between the outdoor unit and the 1st branch pipe;
The pipes between the branch pipes
Gas Liquid Gas Liquid Marks
RAS-3.0~6.5HNBRKQ1 Φ15.88 Φ9.52 Φ15.88 Φ9.52▲ a; b; c
RAS-7.0~8.0HNBRMQ1 Φ19.05 Φ9.52 Φ19.05 Φ9.52▲ a; b; c
RAS-10HNBRMQ1 Φ19.05 Φ12.7 Φ22.2* Φ12.7 a; b; c
RAS-11~12HNBRMQ1 Φ19.05 Φ12.7 Φ25.4* Φ12.7 a; b; c
Notes:
● Mark “▲” represent that if the liquid pipe which is between the outdoor unit and the 1st branch is over than 70 meters, its
diameter should be up size. Thus the Φ9.52 diameter pipe is converted to Φ12.7 diameter pipe.
● Mark “ * ” represent that there are pipe adapters in the outdoor unit, which is used to adjust the gas pipe between the
outdoor unit and the first branch. Thus the Φ19.05 diameter pipe is converted to Φ22.2 diameter pipe in the model of RAS-
10HNBRMQ1, and the Φ19.05 diameter pipe is converted to Φ25.4 diameter pipe in the model of RAS-11~12HNBRMQ1.