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Building Technologies
Modular Heating Controller RMH760B
CE1P3133en
HVAC Products
10 DHW heating
05.02.2007
An additional storage tank sensor can be configured for storage tank charging control.
The storage tank sensor at the bottom allows better usage of the storage tank volume.
The function is to be activated via “Extra configuration”:
… > Inputs > Storage tank sensor bottom
Assign terminal
Main menu > Commissioning > Settings > …
or
Main menu > Settings > DHW > DHW
Operating line
Range
Factory setting
Setback DHW setpoint bottom
0…20 K
5 K
When using an additional storage tank sensor at the bottom of a stratification storage
tank, it can be ensured that the tank will be fully charged.
In the case of storage tanks with good stratification, consideration can also be given to
the anticipated temperature differential by setting the DHW setpoint drop at the bottom
(TStTa SetptRed).
Storage tank charging is started when both temperatures (TStTaTop and TStTaBot)
drop
below their switch-on points (T
on
).
For storage tank charging to end, both temperatures (TStTaTop and TStTaBot) must
exceed
their switch-off point (T
OFF
).
31
3
3D
06
T
TStTaTop
T
TStTaBot
ON
OFF
SDDhw
TStTaSetpt
+
P
ON
SDDhw
TStTaTop
TStTaBot
ON
OFF
TStTaSetptNorm TStTaSetptRed
P
OFF
P
ON
P
OFF
Type of storage tank = stratification storage tank with 2 storage tank sensors
Storage tank temperature setpoint = 55 °C
Switching differential for storage tank charging = 5 K
Setpoint reduction at the bottom for storage tank charging = 3 K
Charging is started when the
2
following conditions are satisfied:
•
Temperature at the top sensor =
≤
50 °C
and
•
Temperature at the bottom sensor =
≤
47 °C
Charging is ended when the
2
following conditions are satisfied:
•
Temperature at the top sensor = >55 °C
and
•
Temperature at the bottom sensor = >52 °C
Charging would be ended with a stratification of 3 K and a storage tank outlet tempera-
ture of 55°C.
Storage tank sensor
at the bottom
Extra configuration
Settings
Storage tank sensor
at top and bottom
Starting storage tank
charging
Ending storage tank
charging
Example
Starting charging
Ending charging
⇒