EWAQ+EWYQ009~0 EWAQ+EWYQ009~013ACW1
Packaged air-cooled water chillers and packaged
reversible air to water heatpumps
4PW51587-1A
Installation manual
10
Connecting the water circuit
Water connections must be made in accordance with the outlook
diagram delivered with the unit, respecting the water in- and outlet.
If air, moisture or dust gets in the water circuit, problems may occur.
Therefore, always take into account the following when connecting
the water circuit:
■
Use clean pipes only.
■
Hold the pipe end downwards when removing burrs.
■
Cover the pipe end when inserting it through a wall so that no
dust and dirt enter.
■
Use a good thread sealant for the sealing of the connections.
The sealing must be able to withstand the pressures and
temperatures of the system.
■
When using non-brass metallic piping, make sure to insulate
both materials from each other to prevent galvanic corrosion.
■
Because brass is a soft
material, use appropriate tooling
for connecting the water circuit.
Inappropriate tooling will cause
damage to the pipes.
Protecting the water circuit against freezing
Frost can damage the unit. For this reason, in colder climates the
water circuit can be protected by means of a heater tape option
(OP10) or by adding glycol to the water.
In case of heater tape
Check that the unit has the option heater tape installed (factory
mounted). Units with option heater tape have the possibility to install
an extra heatertape to protect the waterpipe outside the unit against
freezing. (Field supply, maximum 200 W, connections must be made
on terminals 5/6 inside the switchbox).
In case of glycol
Depending on the expected lowest outdoor temperature, make sure
the water system is filled with a weight concentration of glycol as
mentioned in the table below.
Also refer to
"Checks before initial start-up" on page 16
Charging water
1
Connect the water supply to a drain and fill valve (see
).
2
Make sure the automatic air purge valve is open (at least 2
turns).
3
Fill with water until the manometer indicates a pressure of
approximately 2.0 bar. Remove air in the circuit as much as
possible using the air purge valves. Air present in the water
circuit might cause malfunctioning.
Piping insulation
The complete water circuit, inclusive all piping, must be insulated to
prevent condensation during cooling operation and reduction of the
cooling and heating capacity as well as prevention of freezing of the
outside water piping during winter time. The thickness of the sealing
materials must be at least 13 mm with
λ
= 0.036 in order to prevent
freezing on the outside water piping.
If the temperature is higher than 30°C and the humidity is higher than
RH 80%, then the thickness of the sealing materials should be at
least 20 mm in order to avoid condensation on the surface of the
sealing.
Be careful not to deform the unit piping by using excessive
force when connecting the piping. Deformation of the
piping can cause the unit to malfunction.
■
The unit is only to be used in a closed water system.
Application in an open water circuit can lead to
excessive corrosion of the water piping.
■
Never use Zn-coated parts in the water circuit.
Excessive corrosion of these parts may occur as
copper piping is used in the unit's internal water
circuit.
For the heater tape to operate, power to the unit must be
provided and the main isolator switch must be on. For this
reason never disconnect power and never turn off the main
isolator switch for a long time during cold periods!
Minimum
outdoor temperature
Ethylene glycol
Propylene glycol
–5°C
10%
15%
–10°C
25%
25%
–15°C
35%
35%
Corrosion of the system due to presence of glycol
Uninhibited glycol will turn acidic under the influence of
oxygen. This process is accelerated by presence of copper
and at higher temperatures. The acidic uninhibited glycol
attacks metal surfaces and forms galvanic corrosion cells
that cause severe damage to the system.
It is therefore of extreme importance:
■
that the water treatment is correctly executed by a
qualified water specialist;
■
that a glycol with corrosion inhibitors is selected to
counteract acids formed by the oxidation of glycols;
■
that no automotive glycol is used because their
corrosion inhibitors have a limited lifetime and contain
silicates which can foul or plug the system;
■
that galvanized piping is not used in glycol systems
since its presence may lead to the precipitation of
certain components in the glycol’s corrosion inhibitor;
■
that it has to be made sure the glycol is compatible
with the used materials in the system.
NOTE
Be aware of the hygroscopic property of glycol: it
absorbs moisture from its environment.
Leaving the cap off the glycol container causes the
concentration of water to increase. The glycol
concentration is then lower than assumed. And in
consequence, freezing can happen after all.
Preventive actions must be taken to ensure minimal
exposure of the glycol to air.
NOTE
■
During filling, it might not be possible to remove all
air in the system. Remaining air will be removed
through the automatic air purge valves during first
operating hours of the system. Additional filling
with water afterwards might be required.
■
The water pressure indicated on the manometer
will vary depending on the water temperature
(higher pressure at higher water temperature).
However, at all times water pressure should
remain above 0.3 bar to avoid air entering the
circuit.
■
The unit might dispose some excessive water
through the pressure relief valve.
Содержание EWAQ-ACV3
Страница 29: ...NOTES NOTES ...
