Cordivari 150/12 Mode D'emploi page 14

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Note: be careful not to reverse the connections to the DHW distribution
system, as this will compromise the system's functionality. A typical
connection to an instant DHW tank is also shown below.
VD Diverter valve
MT Thermostatic mixing valve
V1,V2,V3 Shut-off valves
VSR Safety and check valve
Caution!
To avoid any dangers arising from the high temperatures
that can be reached, it is always advisable to install a
thermostatic mixing valve (MT) before sending the water
produced by the solar system to taps.
The shut-off valves V1, V2 and V3 (or similar systems, accessories not
supplied) are necessary as they allow the solar system to be disconnected
from the DHW system for maintenance purposes (for example). The
diverter valve DV (not supplied) can be of a motorised type controlled by
a dedicated thermostat (not supplied and not shown in the diagram), or
else a self-actuated thermostatic type: According to water temperature
at the outlet of the solar DHW tank, it sends the flow directly to taps if
the temperature is sufficient or it deviates the flow to feed the DHW tank,
using in any case the energy available and the partial solar preheating.
Connect the combined temperature and pressure safety valve. It must
be installed after applying hemp or Teflon to the 1/2" F connection on the
rear of the DHW tank.
Caution! Burn Hazard!
High-temperature water can come out of the TP valve drain,
therefore, prevent any injury or damage to people or property.
The TP valve can be subject to malfunctioning if solid
residues are present in the DHW circuit and/or in case of
limescale build-up caused by consistent water hardness
and high temperatures
The warranty will be void if the provisions under the current
regulations concerning water treatment and water system devices
(UNI-CTI 8065) are not complied with. In the case of low or intermittent
hot water use resulting in persistent overheating, it is recommended
to install a properly sized expansion tank within the water circuit in
order to prevent the OF valve from continuously dripping, which would
considerably increase its wear.
3.4.3 Regulatory aspects of DHW tank installation
Verify the presence of the magnesium anode at the installation location,
as well as its proper assembly. The DHW tanks must be installed in
accordance with the current national legislation in the country of use.
In Italy, according to Ministerial Circular No. 829571 of 23/03/03, the
installation of DHW tanks in domestic water systems must be carried
out using a water safety unit. This safety unit must include at least one
shutoff valve, a check valve, a control device for the check valve, a safety
valve (see the next paragraph for its characteristics), and a water load
shut-off device. All these accessories are necessary in order to ensure
the DHW tank's safe operation.
Based on the provisions of collection R ed. 2009 sec. R.1.A, an expansion
system must always be installed, along with appropriate protection
devices (such as thermostats, pressure switches, and minimum pressure/
level protection devices), wherever required. The protective devices are
required for water heaters in which the temperature of the primary circuit
exceeds the boiling point of the secondary fluid at a pressure value of
0.5 bar. The expansion system can simply consist of a relief valve, of a
counterweight or spring type, whose orifice has a minimum diameter (in
millimetres) of:
at least 15 mm, with V being the DHW tank's volume in litres. The valve
must be calibrated to a pressure value that does not exceed the DHW
tank's maximum operating pressure, and must be connected directly
without using any shut-off devices. Furthermore, in order to prevent the
valve from continuously opening, it is recommended to install a closed
type expansion tank with a non-toxic membrane. If domestic hot water
system exceeds the max. permitted DHW tank pressure values, install a
pressure reducer as far as possible from DHW tank. In order to avoid the
effects of any stray galvanic currents it is always necessary to provide a
PROPER GROUNDING of the systems and DHW tank.
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Cod. 1910000002148 - nv00