ENGLISH-27
02 INSTALLATION
Setting the pre-pressure of the expansion vessel
When it is required to change the default pre-pressure of the expansion vessel(1 bar), keep in mind the following guidelines:
Use only dry nitrogen to set the expansion vessel pre-pressure.
Inappropriate setting of the expansion vessel pre-pressure will lead to malfunction of the system. Therefore, the pre-
pressure should only be adjusted by a licensed installer.
[Lit]
50 100 150 200 250 300 350 400
14.00
12.00
10.00
8.00
6.00
4.00
2.00
0.00
Water volume (Litre) in total system including pipes
Operation range
Norminal
Expansion Vessel capacity (Liter)
• Water volume of total system (except tank hydro unit) for reliable performance is minimum 20 liters(AE040/050/
060/080/090RX**), 40 liters(AE120/160RX**).
CAUTION
Installation height
dierence
a)
Water volume
< 220 Litres > 220 Litres
< 7m No pre-pressure adjustment required.
Actions required:
• Pre-pressure must be decreased, calculate
according to “Calculating the pre-pressure of
the expansion vessel”.
• Check if the water volume is lower than
maximum allowed water volume
> 7m
Actions required:
• Pre-pressure must be increased, calculate
the appropriate value following by
“Calculating the pre-pressure of the
expansion vessel”.
• Check if the water volume is lower than
maximum allowed water volume
Expansion vessel of the unit too small for the
installation.
a) Installation height dierence: height dierence(m) between the highest point of the water circuit and the indoor unit. If
the indoor unit is located at the highest point of the installation, the installation height is considered 0m.
Calculating the pre-pressure of the expansion vessel
The pre-pressure(Pg) to be set depends on the maximum installation height dierence(H) and is calculated as below:
Pg=(H/10+0.3) bar