4
S1
A
S2
S3
Hydraulic diagrams
Solar thermal system - program 0
= factory settings
The solar pump
A
runs when S1 has a temperature of
diff1
higher than S2 and S2 has not
exceeded the threshold
max1
.
In addition, the pump’s protective function takes effect: During a standstill, steam can oc-
cur in the system. When automatically switched on again, the pump does not have the re-
quired pressure in the steam phase to lift the fluid level to the collector’s supply line (highest
point in the system). This represents a considerable load on the pump. The collect
or’s excess
temperature shut-down function can be used to block the pump whenever a certain tempera-
ture has been reached at the collector’s sensor until a second threshold, which can also be
set, is fallen short of again. The settings ex works are 130°C for the blockage and 110°C for
the release. The settings can be changed in the menu
MEN
, sub-menu
SYS PF
/
CET
(collec-
tor excess temperature).
Program 1
With this program, the solar thermal system has an
additional
storage limit
max2
via sen-
sor
S3
. There is no guarantee that the actual storage temperature will lead to a cut-off in
time, especially if the reference sensor S2 is installed at the return outlet for the heat ex-
changer.
especially if the reference sensor S2 is installed at the return outlet for the heat exchanger.
Note:
In both programs, the special system status “collector excess temperature reached” is
shown with a blinking
Stat
. Once
Stat
has been selected,
CETOFF
appears for the
c
ollec-
tor’s
e
xcess
t
emperature shut-down function.
Some countries only offer subsidies for the installation of solar thermal systems if the con-
trol units have a function check to detect a sensor defect and a lack of circulation. In the
menu command
F CHCK,
the mechanic can activate this function check for the ESR21. This
is possible for both programs and is disabled ex works. For details, see “system status”.
The entire instruction manual with all schemes and programs can be downloaded
from: www.ta.co.at section DOWNLOADS
S3 for program 1
S1
S2
max1
diff1
Required settings :
max1
…
limit TK
S2
max2
… see program
1
diff1
… coll.
S1
– TK
S2
