STIEBEL ELTRON SOM 7 SI - Manual (Page 18)

SOM 7 SI
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CMN / CMN1 / CMN2:
Collector Minimum
Temperature
Adjustment range 50 - 195°F
Factory setting 50°F
CMX / CMX1 / CMX2:
Maximum Collector
Temperature
Adjustment range:
210 - 380 °F
Factory setting 250 °F
4.1.12 System Cooling Functions.
OCX / OCX1 / OCX2:
System Cooling
Adjustment range OFF/ON
Factory setting OFF
4.1.13 Minimum Collector Temperature Limit
OCN / OCN1 / OCN2:
Collector Minimum
Temperature Limitation
Adjustment range OFF/ON
CFR / CFR1 / CFR2:
Antifreeze Temperature
Adjustment range 15 - 50°F
Factory setting 40°F
4.1.14 Antifreeze Function
OCF / OCF1 / OCF2:
Antifreeze Function
Adjustment range OFF/ON
Factory setting OFF
4.1.11 Collector Emergency Shutdown
Temperature
EM / EM1 / EM2:
Collector Emergency
Shutdown Temperature
Adjustment range
230 - 400 °F,
Factory setting 285 °F
If the collector emergency shutdown temperature (EM/
EM1/EM2) is reached, the solar pump (R1/R2) is deactivated
in order to avoid damaging the solar components. The default
setting is 285°F. If the system is in emergency shutdown
mode the symbol is flashing. The system will not exit this
mode until the temperature measured is 30°F lower than
the value of this setting.
The system cooling function is used to prevent the system‘s
heat exchanger fluid from overheating. This in turn prevents
the degradation of the fluid‘s corrosion inhibitors avoiding
damage to the system components. If the system cooling
function is activated the symbol is flashing.
If the maximum collector temperature (CMX/CMX1/
CMX2) is reached the maximum storage tank temperature
(S MX/S1MX/S2MX) is overridden and the system‘s
circulator pump is turned on, cooling the system‘s HX fluid
using the water in the storage tank. This will continue until
either the collector temperature is measured to be at least
9°F lower than the setting of “CMX/CMX1/CMX2”, the
tank reaches it’s 205°F security-switch-off temperature, or
the collector reaches its collector emergency shutdown
temperature. The last two instances should not occur if the
system is sized and configured properly.
The minimum collector temperature is a temperature which
must be exceeded in order for the solar pump (R1/R2) to
be switched-on. The minimum temperature setting is used to
avoid starting-up the solar pump (or solid fuel boiler charging
pumps) when the temperature of the heat exchanger fluid
is too low. If the minimum temperature feature is activated
the symbol is shown on the display (blinking).
The antifreeze function activates the loading circuit between
collector and tank if the antifreeze temperature is reached
in order to protect the heat exchanger fluid against freezing
or “thickening“. If the antifreeze temperature is exceeded
by 2°F, the loading circuit will be deactivated.
Please note:
As there is only a limited heat quantity of the tank available
for this function, the antifreeze function should only be used
in regions with few days of temperatures around freezing
point.