Water Volume And Expansion Vessel Pressure - LG THERMA V Installation Manual

1,MFL68681810,영영 2017. 7. 1. 영영 12:55 Page 35

Water Volume and Expansion Vessel Pressure

Inside
That means, according to the volume-pressure graph, total water volume of 230 liter is supported as
default. If total water volume is changed because of installation condition, the pre-pressure should be
adjusted to secure proper operation.
- Minimum total water volume is 20 liter.
- Pre-pressure is adjusted by the total water volume. If the indoor unit is located at the highest
position of the water circuit, adjustment is not required.
- To adjust pre-pressure, use nitrogen gas by certificated installer.
2.4
2.1
1.7
1.4
1.0
0.7
0.3
20
Adjusting pre-pressure of expansion vessel is as following :
Step 1. Refer "Volume-Height" table.
If installation scene is belong to Case A, go to Step 2.
Otherwise, if it is Case B, do nothing. (pre-pressure adjustment is not required.)
Otherwise, if it is Case C, go to Step 3.
Step 2. Adjust pre-pressure by following equation.
Pre-pressure [bar] = (0.1xH+0.3) [bar]
where H : difference between indoor unit and the highest water pipe
0.3 : minimum water pressure to secure product operation
Step 3. Volume of expansion vessel is less than installation scene.
Please install additional expansion vessel at the external water circuit.
Volume-Height Table
H < 7m
H ≥ 7m
H : difference between indoor unit and the highest water pipe
V : total water volume of installation scene
expansion vessel is included which is 8 liter capacity with 1 bar pre-pressure.
60 100 140
Maximum total water volume (liter)
V < 230 liter V ≥ 230 liter
Case B Case A
Case A Case C
180 220 260
Installation of Indoor Unit
300 340
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