Giatsu WD2N8B Serie Manuel De L'utilisateur Et D'installation page 90

9.3.3 Water circuit connection
Water connections must be made correctly in
accordance with labels on the outdoor unit, with respect
to the water inlet and water outlet.
CAUTION
Be careful not to deform the unit's piping by
using excessive force when connecting the
piping. Deforming the piping can cause the unit
to malfunction.
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
to prevent dust and dirt entering.
Use a good thread sealant for sealing the
connections. The sealing must be able to withstand
the pressures and temperatures of the system.
When using non-copper metallic piping, be sure to
insulate two kind of materials from each other to
prevent galvanic corrosion.
For copper is a soft material,
use appropriate tools for
connecting the water circuit.
Inappropriate tools will cause
damage to the pipes.
NOTE
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.
When using a 3-way valve or a 2-way valve
in the water circuit. The recommended
maximum changeover time of the valve
should be less than 60 seconds.
9.3.4 Water circuit anti-freeze protection
All internal hydronic parts are insulated to reduce heat
loss. Insulation must also be added to the field piping.
In event of a power failure, the above features would not
protect the unit from freezing.
The software contains special functions using the heat
pump and backup heater (if optional and aviliable) to
protect the entire system against freezing. When the
temperature of the water flow in the system drops to a
certain value, the unit will heat the water, either using the
heat pump, the electric heating tap, or the backup heater.
The anti-freeze function will turn off only when the
temperature increases to a certain value.
Water may enter into the flow switch and cannot be drained
out and may freeze when the temperature is low enough.
The flow switch should be removed and dried, then can be
installed in the unit.
Rotate the flow switch counterclockwise to remove it.
Dry the flow switch completely.
CAUTION
When the unit is not running for a long time, make sure the
unit is powered on all the time. If you want to cut off the
power, the water in the system needs to be drained clean to
avoid the unit and piping system be damaged by freezing.
Also the power of the unit needs to be cut off after water in
the system is drained off.
Ethylene Glycol and Propylene Glycol are TOXIC.
9.4 Filling water
Connect the water supply to the filling valve and open the
valve.
Make sure the automatic air purge valve is open.
Fill with water pressure of approximately 2.0 bar. Remove air
in the circuit as much as possible using the air purge valves.
Air in the water circuit could lead to malfunction of the backup
electric heater.
Do not fasten the black plastic
cover on the vent valve at the
topside of the unit when the
system is running. Open air
purge valve, turn anticlockWise
at least 2 full turns to release air
from the system.
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 the first operating hours of
the system. Topping up the water afterwards might be
required.
The water pressure will vary depending on the water
temperature (higher
temperature). However, at all times water pressure should
remain above 0.3 bar to avoid air entering the circuit.
The unit might drain-off too much water through the
pressure relief valve.
Water quality should be complied with EN 98/83 EC
Directives.
Detailed water quality condition can be found in EN 98/83
EC Directives.
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NOTE
WARNING
NOTE
pressure at higher water