STIEBEL ELTRON SOM 7 PLUS Bedienung Und Installation Seite 43

kWh/MWh: Heat amount
in kWh / MWh
Display channel
2.8.9 ΔT control
DT O /DT1O/DT2O/DT3O:
Start temperature
differential
Setting range 1.0 ... 20.0 K
Factory setting 6.0
DT F/DT1F/DT2F/DT3F:
Stop temperature
differential
Setting range 0.5 ... 19.5 K
Factory setting 4.0
DT S/DT1S/DT2S/DT3S:
Set temperature differential
Setting range 1.5 ... 30.0 K
Factory setting 10.0
RIS/RIS1/RIS2/RIS3:
Rise
Setting range 1 ... 20 K
Factory setting 2 K
2.8.10 Maximum cylinder temperature
S MX/S1MX/S2MX:
Maximum cylinder
temperature
Setting range 4 ... 95 °C,
4 ... 90 °C (Arr 10)
Factory setting 60 °C
2.8.11 'T control (solid fuel boiler and heat exchanger)
Maximum temperature limit
MX3O/MX3F:
Maximum temperature limit
Setting range 0 ... 95 °C
Factory setting:
MX3E 60.0 °C
MX3A 58.0 °C
Minimum temperature limit
MN3O/MN3F:
Minimum temperature limit
Setting range 0 ... 90 °C
Factory setting:
ANL = 2
MN3O 5.0 °C
MN3F 10.0 °C
ANL = 8
MN3O 60.0 °C
MN3F 65.0 °C
The amount of heat is calculated by means of the flow rate entered into FMAX and
the temperatures at the reference sensors S3 (flow) and S4 (return). You can dis-
play the yielded amount of heat if the option Heat metering (4) has been enabled
This is displayed in fractions of kWh in display channel kWh and in fractions of
MWh in display channel MWh. The sum of both channels is the total heat yield.
The total heat amount can be reset. As soon as the heat amount channel is
selected, the symbol
(3) key for approx. 2 seconds to access the counter RESET mode. The display symbol
flashes, and the heat amount is reset to 0. To complete the RESET process,
SET
press as acknowledgement.
SET
Wait approx. 5 seconds if the RESET process is to be terminated. The controller
will then automatically revert to display mode.
Note: The start temperature differential must be at least 1 K greater than the stop
#3 $
temperature differential.
 SET SET
K
Initially the control unit acts as a standard differential control unit. When the
start differential is reached (DT O /DT1O/DT2O/DT3O), the pump starts and,
#3 %
after the drop-out impulse (10 s), operates at minimum speed (nMN = 30%).
The speed is increased by one stage (10%) if the temperature differential

SET SET
reaches the selected set value (DT S/DT1S/DT2S/DT3S). The speed is increased
K
respectively by 10% up to the maximum of 100% with every rise of the
differential by 2 K (RIS/RIS1/RIS2/RIS3). The control characteristics can be
adjusted using the "rise" parameter. The controller switches OFF if the selected
#3 2
stop temperature differential is not reached (DT F/DT1F/DT2F).
 SET SET
If the option "Drainback" (ODB) is enabled, the following values will be assigned
K
to parameters DT O , DT F and DT S :
1(2
DT O =
DT F =
 SET SET
DT S =
K
The values previously set in these parameters are overwritten.
Where the set maximum temperature is exceeded, further heating up of the
2 ,7
cylinder is prevented and thus damaging overheating avoided. Where the
 SET
maximum cylinder temperature is exceeded, the display shows
°C
Note: The controller is equipped with a cylinder safety stop facility that prevents
further heating at 95 °C (system cooling function).
The controller is equipped with its own temperature differential controller for
,7.
additionally limiting the minimum and maximum temperature as well as for
 SET
enabling the setting of the associated start and stop temperatures. Only possible
°C
with ANL = 2 and 8 (e.g. for solid fuel boiler or heat exchanger control).
Relay 2 is disabled if the selected value MX3O is exceeded. The relay drops in
,7%
again if parameter MX3F is not achieved.
Relay 2 is disabled if the selected value MN3O is not achieved. The relay drops in
 SET
°C
again if parameter MN3F is exceeded.
In parallel, the start and stop temperature differentials DT3O and DT3F apply to
the maximum as well as the minimum temperature limit.
,-.
 SET
°C
,-%
 SET
°C
appears continuously on the display. Hold down the SET
SET
10 K
4 K
15 K
.
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