LG THERMA V AHNW16606B0, Installation Manual, Page: 31 / 65

Installation of Indoor Unit
Installation Manual 31
ENGLISH
Setting the pressure for the expansion vessel
P
0
• Before filling the system with water, check and set the pressure P
0
. The expansion vessel is
factory set to the pressure specified on its data label. For correct operation of the system, set the
pressure
P
0
according to the equation below. The filling must not exceed the maximum operational
pressure specified on the data label of the expansion vessel.
• Calculate the P
0
pressure value with the help of the equation:
P_
0
[ MPa ] =
P_
rv
[ MPa ] -0.02 [ MPa ],
( P_
0
[ bar ]= P_
rv
[ bar ] -0.2 [ bar ])
P
0
– pressure in the expansion vessel
P
rv
– setting of the pressure reducing valve
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
[0.1 MPa (1 bar)] – pressure in the expansion vessel,
P
0 m
in [0.1 MPa (1 bar)] – minimum allowed pressure of the heating system,
P
0 m
ax [0.1 MPa (1 bar)] – maximum allowed pressure of the heating system,
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
0
on the data label.
• 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
F
.
P
F
[MPa] =
P
0
[MPa] + 0.03 [MPa]
( P
F
[bar] = P
0
[bar] + 0.3 [bar])
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
E
[MPa] ≤
P
sv
[MPa] - 0.05 [MPa]
( P
E
[bar] ≤ P
sv
[bar] - 0.5 [bar])
P
E
– the final pressure of the system,
P
SV
– the pressure of the safety valve.