LG THERMA V Series Installation Manual page 31

Setting the pressure for the expansion vessel
• Before filling the system with water, check and set the pressure P
factory set to the pressure specified on its data label. For correct operation of the system, set the
pressure P according to the equation below. The filling must not exceed the maximum operational
0
pressure specified on the data label of the expansion vessel.
• Calculate the P pressure value with the help of the equation:
0
– pressure in the expansion vessel
P
0
P – setting of the pressure reducing valve
rv
If the calculation shows a pressure lower than 0.1 MPa (1 bar), set the pressure of the expansion
vessel to 0.1 MPa (1 bar).
P [0.1 MPa (1 bar)] – pressure in the expansion vessel,
0
P in [0.1 MPa (1 bar)] – minimum allowed pressure of the heating system,
0 m
ax [0.1 MPa (1 bar)] – maximum allowed pressure of the heating system,
P
0 m
H [m] – Height of the heating system.
• Set the amount of pressure in the expansion vessel by releasing or adding dry nitrogen.
• Record the new value of the pressure P
• Open the closing valve of the expansion vessel carefully, open the vents and close the drain.
Filling the heating system
• Use the filling valve to fill the system with water of suitable quality (with anti-corrosion additives,
etc.) to the pressure P
Filling the system to the final pressure
• The final pressure of the system is determined by heating the system to the maximum heating
temperature (thermal degassing).
• Turn off the circulation pumps, open the vents and vent the system.
• Fill the system up to the final pressure which is 0.05 MPa (0.5 bar) lower than the venting pressure
of the safety valve.
P – the final pressure of the system,
E
– the pressure of the safety valve.
P
SV
[MPa] = P_
P_
0
(P_ [bar]= P_
0
on the data label.
0
.
F
P [MPa] = P
F
(P [bar] = P
F
P [MPa] ≤ P
E
(P [bar] ≤ P
E
. The expansion vessel is
0
[MPa] -0.02 [MPa],
rv
[bar] -0.2 [bar])
rv
[MPa] + 0.03 [MPa]
0
[bar] + 0.3 [bar])
0
[MPa] - 0.05 [MPa]
sv
[bar] - 0.5 [bar])
sv
Installation of Indoor Unit
0
Installation Manual 31