Time-controlled switchover of storage tank sensors
By configuring a second storage tank sensor SF2 over the function block CO4 -> F19 -1, it is
possible to determine that the storage tank sensor SF1 is used for day mode in the DHW cir-
cuit and that the storage tank sensor SF2 is used for night mode. As a result, different stor-
age tank volumes can be kept at a constant temperature according to a time schedule, and
also at different temperatures if the
DHW set point and Sustained DHW temperature differ
from one another.
Stop storage tank charging
The controller stops charging the storage tank when the water temperature measured at sen-
sor SF1 has reached the temperature T =
DHW tempe hysteresis. When there is no
heating operation or when the flow temperature demand in the system is lower, the corre-
sponding valve is closed.
The storage tank charging pump is switched off after t =
lag time of storage tank charging
pump x valve transit time.
With the default settings, the temperature in the storage tank is increased by 5 °C to reach
50 °C when the the storage tank temperature falls below 45 °C. The charging temperature is
calculated from the DHW temperature (45 °C) plus the charging temperature boost (10 °C),
which equals 55 °C. When the storage tank has been charged, the heating valve is closed
and the charging pump continues operation for the time t (lag). Outside the times-of-use, the
storage tank is only charged when the the temperature falls below 40 °C (
Sustained DHW
temperature). In this case, the tank is charged with a charging temperature of 50 °C until
45 °C are reached in the tank.
Functions
WE
Configuration
Storage sensor SF1
1
CO4 -> F01 - 1
Storage sensor SF2
CO4 -> F02 (- 1 when CO4 -> F19 - 1)
SLP ON depending on return flow temperature
0
CO4 -> F15
Time-controlled switchover of storage sensors
0
CO4 -> F19 (-1 only when CO4 -> F02 - 1)
Parameter
WE
Rotary switch / Range of values
DHW temperature set point or charging temper-
ature set point with CO4 -> F01 - 0
55 °C
Bottom / Min. to max. DHW
temperature
Parameters
WE
Parameter level / Range of values
Min. DHW temperature*
40 °C
PA4 / 20 to 90 °C
Max. DHW temperature*
60 °C
PA4 / 20 to 90 °C
Hysteresis**
5 °C
PA4 / 0 to 30 °C
62
EB 5576 EN
Functions of the DHW circuit
