Rittal LCU DX
17
6 Installation
EN
7. For intake gas lines laid vertically with the direction of
flow pointing upwards (external unit is above the in-
ternal unit), an oil elevation arc should be provided at
least every 3 m of line length. The pre-insulated pairs
of lines may be laid with no distance between them.
Protecting the pipework
1. Suitable precautions should be taken to prevent ex-
cessive vibrations or pulsations. In particular, care
should be taken to prevent the direct transmission of
noise or vibrations onto or through the supporting
structure and the connected devices.
2. Safety devices, pipework and fittings should be pro-
tected from unfavourable environmental influences
as far as possible. Due consideration should be giv-
en to unfavourable environmental influences, such
as the risk of water collecting, relief lines freezing, or
dirt and waste accumulating.
3. With long pipelines, adequate precautions should be
taken with regard to expansion and contraction.
4. The pipelines of cooling systems should be de-
signed and laid in such a way that the system cannot
be damaged by liquid slugging (hydraulic shock).
5. Pipelines with detachable connections must not be
positioned in public thoroughfares, vestibules, stair-
wells, steps, entrances, exits or in ducts or shafts
with unsecured openings to such areas, unless pro-
tected against disconnection.
6. Pipelines without detachable connections, valves,
control and regulatory devices that are protected
against accidental damage may be positioned in
public thoroughfares, stairwells or vestibules, pro-
vided they are situated at least 2.2 m above the
ground.
Pipe supports
1. Both horizontal and vertical lines must be laid with vi-
bration-damping elements (such as rubber seals).
These must be used at a spacing of at least 2 m.
2. Take care to ensure that the first pipe support be-
hind the internal unit and in front of the external unit
does not exert any mechanical pressure (via the
pipe) on the component. Pipe supports must not be
located too close to bends, to give the lines space
to expand.
Create the pipework system
1. To create the refrigerant pipework system, open the
ends of the lines on the internal unit. Upon opening,
gas should flow out audibly (from the nitrogen filling
provided in the factory) as an indication that there
are no leaks in the cooling circuit.
2. Only cut pipes to length using a pipe cutter.
3. Never saw pipes, as this could create swarf.
4. Only solder pipes under nitrogen or helium! To this
end, allow dry inert gas to flow into the pipe at one
end of the pipeline which has already been created.
Before starting, introduce a powerful current, reduce
this to a minimum when you start soldering, and
maintain this weak flow of protective gas throughout
the entire soldering process.
5. Before soldering the final connection, loosen the
screw connection on the external unit, or leave it un-
tightened throughout, so that overpressure cannot
build up in the pipeline system. Immediately after
soldering, tighten the screw connection.
6. The pipelines may only be connected to the external
unit with flares. However, flare connections should
be restricted to soft pipes! After cutting the pipes to
length, adjust to the correct internal diameter with
light flaring. The flares must be tightened with the
prescribed torque using a torque wrench.
Low-temperature insulation of the liquid line and
intake gas line
1. Both lines outside and inside the building should be
equipped with low-temperature insulation to DIN
4140 made from UV-resistant HT/Armaflex or an
equivalent material.
2. We recommend a wall thickness of 9 mm
Leak test / conducting the leak test
The system must undergo leak testing as a complete
system. A test should also be carried out on site once
the installation is complete.
Multiple techniques may be used to test for leaks, de-
pending on the manufacturing conditions, such as pres-
surisation with inert gas, or leak detection using radioac-
tive gas. In order to avoid emissions of hazardous sub-
stances, the pressure test may be carried out with inert
gas such as nitrogen, helium or carbon dioxide. Oxy-
acetylene and hydrocarbons must not be used for safety
reasons. Air and gas mixtures are to be avoided, since
certain mixtures may be hazardous.
The manufacturer must select a test method which al-
lows suitable results to be achieved in accordance with
the requirements outlined below.
Note:
Vibrations and pulsations should be as-
sessed with the system operational at maxi-
mum condensation temperature and when
switching the system on and off, which has
unfavourable impacts on the pipework.
Note:
The internal unit is pressurised (filled with pro-
tective gas)!
