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4 .10 Water circuit
WORKING PRESSURE
The maximum working pressure of the boiler is 6 bar (600
kPa) whilst the minimum is 0.5 bar (50 kPa).
b
It is compulsory to install devices along the topping
up/supply line as well as the water circulation system
to protect the installation from pressures exceeding
550 kPa, in conformity to prescriptions given in the
EN 60335-2-102.
b
Do not expose the exchanger to cyclic changes
in pressure as fatigue stress does a lot of harm to
the system components. Should the water system
suddenly start generating changes in pressure it is
compulsory to use the protection devices to make the
boiler work at a regular pressure.
b
Installation pressure control must be done under cold
conditions.
FILLING UP THE BOILER
The boiler must be filled up by connecting the water from to
the mains to any part of the installation.
b
It is compulsory to use a standard filling device
(EN61770 type) for coupling up to the mains
specifically preventing the back-flow of liquid from
installation to water mains.
EMPTYING THE BOILER
The boiler is emptied through special emptying cocks
installed on the exchanger and water separator.
4 .11 Exhaust flue
12
The exhaust flue duct and fitting to the flue duct must be
made in conformity to standards, legislation in force and to
local rules and regulations.
It is compulsory for ducts to be stiff, resistant to temperature,
condensate, mechanical stress and be sealed.
The flue duct must be as straight as possible, sealed and
insulated.
It must not have any occlusions or narrowing.
Maximum length of the exhaust flue duct (with a diameter of
Ø110 mm) is 55 metres.
Keep in mind that a 90° elbow equals 4 metres of straight
pipe and a 45° elbow one metre of straight pipe.
b
The boiler's total potential exceeds 35 kW and can
therefore only be installed in premises with air vents
opening towards the outside and made in conformity
to provisions of the law in force (Ministerial Decree
D.M. 12.04.1996).
a
DO NOT for any reason use piping not specifically
designed for this specific scope as the condensing
action could cause rapid degradation.
a
In the event of installation with air intake from the
premises (both in the heating unit and externally)
avoid obstructing the passage of air under the metal
cupboard.
5
INSTALLATION DIAGRAMS
An installation diagram must generally be adapted to the
manufacturing characteristics of the relevant heating unit,
with the purpose of exploiting the boiler potentials to the
full and maintain the entire installation efficient for as long
as possible.
The electronic modulating circulator placed inside the
appliance is only for the primary system and works to keep
the ΔT constant with changes in power modulation. The ΔT
value is set at 20° in the factory and may be altered by
specialized personnel only.
The installation circulators must be scaled to the project
flow capacity and load-loss of said installation only. If the
distribution kits, provided as an accessory, are installed it
will be necessary to check that the technical features of the
low. system circulators and mixer valve are compatible with
the installation.
The Figure 10 shows the water diagram of the unit and
a typical system connectable to the latter, with the three
high, low temperature and hot water systems. Everything
in the large box with dotted lines is in the interior of the
unit. The circulation part in the shaded area is available
as an accessory distribution kit; otherwise it will have to be
installed on the outside of the system.
The Figure 11 shows the accessory distribution kits
installable inside the cupboard.
b
Distribution kits are equipped with shut-off valves.
These must be installed in appropriate places on the
installation.
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