Changing The Pre-Pressure Of The Expansion Vessel - Daikin ERRA08-12EW1 Installer's Reference Manual

8.5.4 Changing the pre-pressure of the expansion vessel

ERRA08~12E + ELVH/X12S18+23E
Daikin Altherma 3 R MT F
4P708474-1 – 2023.05
Installation
height
(a)
difference
>7 m Do the following:
▪ Increase the pre-pressure
according to the required
installation
difference. The pre-pressure
should increase by 0.1 bar
for each metre above 7 m.
▪ Check if the water volume
does
maximum
volume.
(a)
This is the height difference (m) between the highest point of the water circuit and the
indoor unit. If the indoor unit is at the highest point of the installation, the installation
height is 0 m.
Minimum flow rate
Check that the minimum flow rate in the installation is guaranteed in all conditions.
For this purpose, use the differential pressure bypass valve delivered with the unit,
and respect the minimum water volume.
If operation is...
Cooling
Heating/defrost
NOTICE
When circulation in each or certain space heating loops is controlled by remotely
controlled valves, it is important that the minimum flow rate is guaranteed, even if all
valves are closed. In case the minimum flow rate cannot be reached, a flow error 7H
will be generated (no heating or operation).
See the recommended procedure as described in
4
commissioning" [ 258].
NOTICE
ONLY a licensed installer may adjust the pre-pressure of the expansion vessel.
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.
▪ 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.
Water volume
≤200 l
The expansion vessel of the
indoor unit is too small for the
installation. In this case, it is
recommended to install an
height
extra vessel outside the unit.
NOT exceed the
allowed water
Then the minimum required flow rate
8 Piping installation
|
>200 l
is...
10 l/min
20 l/min
"12.4 Checklist during
Installer reference guide
115