Lamborghini Caloreclima MEGA 92 Notice D'installation, Utilisation Et Entretien page 47

SUPPLY WATER
The chemical characteristics of the supply and top-up water are fundamental for the correct operation and the safety of the boiler.
The water should be treated using suitable systems.
The values shown in the table below can be used as references.
TOTAL HARDNESS ppm
ALKALINITY mg/l CaCO
PH 8÷9
SILICA ppm
CHLORIDES ppm
The water used in the central heating system must be treated in the following cases:
- Very large systems
- Very hard water
- Frequent introduction of water to top up the system
If, in these cases, the system needs to be partially or completely emptied, it must be refilled with treated water.
To control the volume of water automatically refilled, an hour counter should be installed.
The most common phenomena that occur in heating systems are:
- Lime scale deposits
Lime scale tends to concentrate at the points where the temperature of the wall is higher.
Due to their low heat conductivity, lime scale deposits cause a reduction in heat exchange to the extent that even when just a few
millimetres thick, the heat exchange between the flue gas and the water is limited, bringing an increase in the temperature of the
parts exposed to the flame and consequently breakages (cracks) on the tube plate.
- Corrosion on the water side
Corrosion of the metal surfaces on the water side of the boiler is due to the dissolution of iron into its ions.
The presence of dissolved gases, in particular oxygen and carbonic dioxide, play and important part in this process.
Softened and/or demineralised water provides protection against lime scale and other deposits, however does not protect against
corrosion. The water therefore must be treated with corrosion inhibitors.
CENTRAL HEATING OUTLET/RETURN PIPES
Check that the system features a sufficient number of vent openings. The boiler fittings must not be stressed by the weight of the
connection pipes to the system, and consequently special supports must be installed (see the table on page 44).
SYSTEM FILL/DRAIN PIPES
To fill and drain the boiler, a cock can be connected to fitting T4 at the rear (see the table on page 44).
EXPANSION VESSEL AND SAFETY VALVE PIPES
The MEGA boilers are suitable for operation with forced water circulation, both with open and closed expansion vessels.
An expansion vessel is always required, to allow for the increase in water volume due to heating. In the first case, the height of the
hydrostatic column must be at least 3 metres above the boiler casing and must have a sufficient capacity to contain, between the
surface of the water in the vessel and the overflow pipe, the increase in volume of all the water in the system. High and narrow ves-
sels are better, as they ensure minimum contact between the water surface and the air, thus reducing evaporation.
In the second case, the capacity of the closed expansion vessel must be calculated considering:
- the total volume of water contained in the system
- the maximum operating pressure of the system
- the maximum operating pressure of the expansion vessel
- the initial pre-charge pressure of the expansion vessel
- the maximum operating temperature of the boiler (the maximum temperature of the thermostat fitted on the panel is 90°C; when
performing this calculation, use the value 100°C).
The expansion pipes connect the expansion vessel to the system. The pipes that run from fitting T3 (see the table on page 44), must
not be fitted with on-off valves. On fitting T3, or on the outlet pipe, within 0.5 metres from the first flange, install a safety valve sized
for the capacity of the boiler and in compliance with the local standards in force. No type of shut-off device may be installed betwe-
en the boiler and the expansion vessel, and between the boiler and the safety valves, while the valves should calibrated for activa-
tion at values no higher than the maximum admissible operating pressure.
10
750
3
100
3500
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INSTALLATION