Daikin ALTHERMA, Installer'S Reference Manual

Page: 79 / 280

8 | Piping installation
Installer reference guide
79
EBLA09~16DA + EDLA09~16DA
Daikin Altherma 3 M
4P620241-1 – 2020.06
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 "12.4 Checklist during
commissioning" [ 4 222].
8.1.4 Changing the pre-pressure of the expansion vessel
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.
a
a Schrader valve
8.1.5 To check the water volume: Examples
Example 1
The outdoor 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 outdoor unit is installed at the highest point in the water circuit. The total
water volume in the water circuit is 250 l.
Actions:
▪ 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