Refrigerant And Water Pipe Work; General Notes Before Performing Pipe Work; Suspension Of Refrigerant And Water Pipes - Hitachi RAS-H(V)RNME-AF Service Manual

3 Piping work and
refrigerant charge

3.1 Refrigerant and water pipe work

3.1.1 General notes before performing pipe work

1 Prepare locally-supplied copper pipes.
2 Select the piping size with the correct thickness and correct material able to withstand sufficient pressure.
3 Select clean copper pipes. Make sure that there is no dust or moisture inside the pipes. Blow the inside of the pipes
with oxygen free nitrogen to remove any dust and foreign materials before connecting them.
N O T E
A system with no moisture or oil contamination will give maximum performance and lifecycle compared to that
of a poorly prepared system. Take particular care to ensure that all copper piping is clean and dry internally.
There is no refrigerant in the cycle of the indoor unit.
C A U T I O N
Cap the end of the pipe when pipe is to be inserted through a wall hole.
Do not put pipes on the ground directly without a cap or vinyl tape at the end of the pipe.
If piping installation is not completed until next day or over a longer period of time, braze off the ends of the piping and char-
ge with oxygen free nitrogen through a Schrader valve type access fitting to prevent moisture and particle contamination.
Do not use insulation material that contains NH3, as it can damage copper pipe material and become a source of future
leakage.
Completely insulate both refrigerant gas piping and liquid piping between the indoor unit and the outdoor unit.
If not insulated, in cooling mode and high ambient humidity conditions, dew will appear on the piping surface.
Refrigerant circuit and Water circuit must be performed and inspected by a licensed technician and must comply with all
relevant European and national regulations.

3.1.2 Suspension of refrigerant and water pipes

Suspend the refrigerant and water piping at certain points and prevent the refrigerant and water piping from being in direct
contact with the building: walls, ceilings, etc...
If there is direct contact between pipes, abnormal sound may occur due to the vibration of the piping. Pay special attention
in cases of short piping lengths.
56
SMGB0070 rev.1 - 08/2011
1~15m
Fire-Proof Section
Treatment
Indoor unit