Viessmann SCU345 Manual page 46

Collector emergency shutdown
COL(1,2) / CEM(1,2)
Collector temperature limitation
Adjustment range: 80 ... 200 °C [170 ... 390 °F]
in steps of 1 °C [2 °F]
Factory setting: 130 °C [270 °F]
Switch-on hysteresis: -10 K [-20 °Ra]
When the collector temperature exceeds the ad-
justed collector emergency temperature (CEM /
CEM1 / CEM2), the solar pump (R1 / R2) is switched
off in order to protect the system components against
overheating (collector emergency shutdown). If the
maximum collector temperature is exceeded,
displayed (fl ashing).
Collector cooling
COL(1,2) / OCCO(1,2)
Selection: OFF / ON
Factory setting: OFF
This function is used for keeping the system tempera-
tures and consequently the thermal load as low as
possible.
When the tank temperature exceeds the adjusted
maximum tank temperature, the solar system is
switched off. If the collector temperature increases
to the adjusted maximum collector temperature, the
46
solar pump is activated until the collector tempera-
ture falls below the maximum collector temperature.
The tank temperature may then exceed the maximum
temperature, but only up to 95 °C [200 °F] (emer-
gency shutdown of the tank).
If the collector cooling is active,
(fl ashing).
COL (1,2) / OCCO(1,2) / CMAX(1,2)
Collector maximum temp.
Adjustment range: 70 ... 160 °C [150 ... 320 °F]
in steps of 1 °C [2 °F]
Factory setting: 110 °C [230 °F]
Switch-on hysteresis: -5 K [-10 °Ra]
is
Note
This function is only available, if the system
cooling function and the heat dump function
are deactivated.
Minimum collector limitation
COL(1,2) / OCMI(1,2)
Collector minimum temp.
Selection: ON / OFF
Factory setting: OFF
is displayed
COL (1,2) / OCMI(1,2) / CMIN(1,2)
Collector minimum temp.
Adjustment range: 10.0 ... 90.0 °C [50.0 ... 190.0 °F]
in steps of 0.5 °C [1.0 °F]
Factory setting: 10.0 °C [50.0 °F]
The minimum collector temperature is the minimum
switch-on temperature which must be exceeded
for the solar pump (R1 / R2 / R3) to switch on. The
minimum temperature prevents the pump from being
switched on too often at low collector temperatures.
If the collector temperature falls below the adjusted
minimum temperature,
Evacuated tube collector function
COL / OTCO (1, 2)
Evacuated tube collector function
Selection: ON / OFF
Factory setting: OFF
is displayed (fl ashing).