7
This process may
not
be carried out while the solar
thermal system is in operation.
1.
Cover the collectors with tarpaulins.
2.
Determine the charge pressure:
■
Solar thermal system pressure
1 bar + 0.1 bar/m
= system pressure
■
System pr 0.1 bar pressure reserve for
ventilation
3.
Determine the pre-charge pressure of the expan-
sion vessel:
Value for system pressure minus 0.3 bar for
hydraulic seal.
4.
Check pre-charge pressure and adjust if required.
A pressure gauge can be found in the
solar serv-
ice case
available as an accessory.
5.
Enter the values in the following table (for subse-
quent inspection and maintenance work).
Example:
At 10 m static head, the result is:
■
System pressure = 2 bar
■
Charge pressure = 2.1 bar
■
Pre-charge pressure = 1.7 bar
P
2
4
1
3
5
5
Fig.1
1
System pressure of the solar thermal system
1.0
bar
2
Supplement, static head 0.1 bar/m
................
bar
3
System pressure (pressure gauge)
................
bar
Pressure reserve for ventilation
+ 0.1
bar
Charge pressure
................
bar
Pre-charge pressure of expansion vessel
5
Note
Record the "pre-charge pressure" level on the expansion vessel.
................
bar
4
Supplement 0.1 bar/m
................
bar
Commissioning, inspection, maintenance
Checking pressure conditions and adjusting the pre-charge pressure of the
expansion vessel if necessary
5675 801 GB
