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Viessmann 5443202
21
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SCU124
Maximum tank temperature
Once the adjusted maximum temperature is exceeded,
the solar pump is switched off and further loading of the
tank is prevented to reduce scald risk or system damage. A
fixed hysteresis of 4 °Ra [2 K] is set for the maximum tank
temperature.
When the temperature at the sensor 2 exceeds the adju-
sted maximum tank temperature, the
symbol is shown
on the display.
S MX:
Maximum tank temp.
Adjustment range:
40 ... 200 °F
[4 ... 95 °C]
Arr 3:
40 ... 190 °F
[4 ... 90 °C]
in steps of 2 °Ra [1 K]
Factory setting:140 °F [60 °C]
Note:
If the collector cooling or the system cooling
function is activated, the adjusted tank tempe-
rature may be overridden. In order to prevent
system damage, the controller is also equipped
with a non-adjustable emergency shutdown if the
tank reaches 200 °F [95 °C].
Collector temperature limitation
Emergency shutdown of the collector
If the adjusted collector emergency shutdown temperature
EM is exceeded, the controller switches off the solar pump
(R1) in order to protect the system against overheating
(collector emergency shutdown). A hysteresis of 20 °Ra
[10 K] is set for the collector temperature limitation. While
the collector is in emergency shutdown,
(flashing) is
shown on the display.
EM:
Collector temperature limitation
Adjustment range:
170 ... 390 °F
[80 ... 200 °C]
in steps of 2 °Ra [1 K]
Factory setting:
270 °F [130 °C]
Note:
If the drainback option ODB is activated,
the adjustment range of EM is changed to
170 ... 250 °F [80 ... 120°C]. The factory setting
in that case is 200 °F [95 °C].
WARNING!
Danger of injury and system da-
mage through pressure surges!
If water is used as a heat transfer
medium in a pressure-less system,
the water will start boiling at 212 °F
[100 °C].
Î
If a pressure-less drainback
system is used with water as a
heat transfer medium, do not
adjust the collector tempera-
ture limitation EM to more
than 200 °F [95 °C]!
