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Piping installation
Installer reference guide
81
ERGA04~08EAV3(A) + EHBH/X04+08EA/EJ6V+9W
Daikin Altherma 3 R W
4P629085-1 – 2020.08
The default pre-pressure of the expansion vessel is 1 bar. When it is required to
change the pre-pressure, take following guidelines into account:
▪
Only use dry nitrogen to set the expansion vessel pre-pressure.
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Inappropriate setting of the expansion vessel pre-pressure will lead to
malfunction of the system.
Changing the pre-pressure of the expansion vessel should be done by releasing or
increasing nitrogen pressure through the Schrader valve of the expansion vessel.
a
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3
a
Schrader valve
8.2.5 To check the water volume: Examples
Example 1
The indoor unit is installed 5 m below the highest point in the water circuit. The
total water volume in the water circuit is 100 l.
No actions or adjustments are required.
Example 2
The indoor unit is installed at the highest point in the water circuit. The total water
volume in the water circuit is 250 l.
Actions:
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Because the total water volume (250 l) is more than the default water volume
(200 l), the pre-pressure must be decreased.
▪
The required pre-pressure is:
Pg = (0.3+(H/10)) bar = (0.3+(0/10)) bar = 0.3 bar
▪
The corresponding maximum water volume at 0.3 bar is 290 l. (See the graph in
▪
Because 250 l is lower than 290 l, the expansion vessel is appropriate for the
installation.
