Immergas MAGIS M4-30 Use And Installation page 72

3,3
2,8
2,3
1,8
1,3
0,8
0,3
0
Example 1
The unit is installed 5 m below the highest point of the water circuit. The total volume of the water in the water circuit is
100L. In this example, no action or adjustment is necessary.
Example 2
The unit is installed at the highest point of the water circuit. The total volume of the water in the water circuit is 250L.
Result:
• Since 250L are more than 230L, the pre-pressure must be decreased (see previous table).
• The required pre-pressure is Pg(bar)=(H(m)/10+0.3))bar = (0/10+0.3)bar = 0.3bar
• The corresponding maximum water value can be read from the chart: indicatively 310L.
• Since the total water volume (250L) is less than the maximum water volume (310L), the expansion vessel is sufficient for
the installation.
Setting of the expansion vessel pre-pressure.
When the default pre-pressure of the expansion vessel (1.0 bar) needs to be modified, follow the guidelines:
• Use only dry nitrogen to adjust the pressure of the expansion vessel.
• An incorrect setting of the expansion vessel pre-pressure would cause the system to malfunction. Pre-pressure must only
be adjusted by an authorised installer.
Selection of the additional expansion vessel.
If the expansion vessel of the appliance is too small for the installation, a further expansion vessel is necessary.
• Calculate the expansion vessel pre-pressure Pg(bar)=(H(m)/10+0.3))bar. The expansion vessel in the unit should also
adjust the pre-pressure.
• Calculate the necessary volume of the additional expansion vessel:
V1=0.0693*Vwater/(2.5-Pg)-V0
Vwater is the water volume in the system, V0 is the volume of the expansion vessel the unit is supplied with (L).
A2
50 100
Volume massimo dell'acqua [L]
Maximum water volume [L]
Pre-pressure = expansion vessel pre-pressure
Pre-pressione = pre-pressione del vaso di espansione
Maximum water volume = maximum water volume in the system
Volume massimo dell'acqua = volume massimo dell'acqua nel sistema
A1 System without glycol A1 Sistema senza glicole
A2 Sistema con il 25% di glicole propilenico
A2 System with 25% propylene glycol
A1
150 200 250
72
300 350