Hitachi RAS-8.0HNBRMQ1 - Refrigerant Piping Size

24
4.3 Refrigerant Piping Size
Example of connection: connection of 4 indoor units.
Table 4.1 Piping Size of Main Pipe
Model
Stop Valve(mm)
Pipe between the outdoor unit and the rst 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 between the outdoor unit and the rst 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 rst 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.
● The piping size (L1, L2, L3, d) of indoor units differ with indoor unit model, please refer to Installation and Maintenance Manual
attached to each indoor unit.
Table 4.2 Piping Work Conditions
Item Marks
Allowable Piping Length
Maximum Piping
Length
(Liquid Pipe)
Between the outdoor unit and the farthest indoor unit a+b+c+d
RAS-3.0~3.5HNBRKQ1 ≤65 meters
RAS-4.0~5.0HNBRKQ1 ≤70 meters
RAS-6.0~6.5HNBRKQ1 ≤85 meters
RAS-7.0~12HNBRMQ1 ≤100 meters
Total liquid pipe length
a+b+c+d+
L1+L2+L3
RAS-3.0~3.5HNBRKQ1 ≤100 meters
RAS-4.0~5.0HNBRKQ1 ≤120 meters
RAS-6.0~6.5HNBRKQ1 ≤150 meters
RAS-7.0~12HNBRMQ1 ≤180 meters
Between the rst branch pipe and the farthest indoor unit b+c+d ≤40 meters
Between branch pipes and connected indoor units L1,L2,L3,d ≤15 meters
Allowable Height
Difference
Outdoor unit is higher than indoor unit H1
RAS-3.0~6.5HNBRKQ1 ≤30 meters
RAS-7.0~12HNBRMQ1 ≤50 meters
Outdoor unit is lower than indoor unit H1
RAS-3.0~6.5HNBRKQ1 ≤30 meters
RAS-7.0~12HNBRMQ1 ≤40 meters
Height difference between indoor units H2 ≤15 meters
Others The model of branch pipe▲
RAS-3.0~6.5HNBRKQ1
RAS-7.0~12HNBRMQ1
E-102SN
NOTE:
Mark “▲” represent that the model of branch pipe should be same as the requirement of the table above.