8 Operating and display functions
22 Installation instructions 0020237057_00
8.11.6 Setting the flow rate of the solar circuit
Menu → Installer level → System configuration → [Solar
circuit ----] → Solar flow volume
– In this function, enter the value for the volume flow. This
value is used to calculate the solar yield.
If a VMS 70 is installed in the system, VMS 70 supplies the
value for the volume flow. The controller ignores the value
that is entered in this function.
8.11.7 Activating Solar pump boost
Menu → Installer level → System configuration → [Solar
circuit ----] → Solar pump boost
– This function allows you to activate a pump kick for the
solar pump, in order to speed up the temperature record-
ing of the collector temperature.
Depending on the design, there is a time delay in some col-
lectors during calculation of the measured value for temper-
ature recording. You can use the Solar pump boost func-
tion to reduce the time delay. When this function is activated,
the solar pump is switched on for 15 seconds (solar pump
boost) if the temperature at the collector temperature sensor
has risen by 2 K/hour. This transports the heated solar fluid
to the point of measurement more quickly.
8.11.8 Setting the solar circuit protection
Menu → Installer level → System configuration → [Solar
circuit ----] → Solar circuit prot.
– With this function, you can define a temperature
threshold for the calculated collector temperature in the
solar circuit.
If the available solar heat exceeds the current heat demand
(e.g. all cylinders fully charged), the temperature in the col-
lector field may rise steeply. If the protection temperature
set at the collector temperature sensor is exceeded, the
solar pump is switched off to protect the solar circuit (pump,
valves, etc.) against overheating. The solar pump is switched
back on once the system has cooled down (35 K hysteresis).
8.11.9 Setting the minimum collector temperature
Menu → Installer level → System configuration → [Solar
circuit ----] → Min. collector temp
– You can use this function to set the minimum collector
temperature.
Defining the switch-on differential for solar charging
(→ Page 22)
8.11.10 Setting the purging time for the solar
circuit
Menu → Installer level → System configuration → [Solar
circuit ----] → Purging time
– This function supports the purging of the solar circuit.
The controller stops the function once the specified purging
time has elapsed, the solar circuit protection function is act-
ive or the max. cylinder temperature has been exceeded.
8.11.11 Reading the current flow rate for the
VMS 70
Menu → Installer level → System configuration → [Solar
circuit ----] → Current flow rate
– You can use this function to read the measured flow rate
(volume flow) for the VMS 70.
8.12 Solar cylinder 1
8.12.1 Defining the switch-on differential for solar
charging
Menu → Installer level → System configuration → [Solar
cylinder 1 ----] → Switch-on diff.
– This function allows you to define a differential value
for starting solar charging. The temperature difference
is measured between the lower cylinder temperature
sensor and the collector temperature sensor.
If the temperature difference exceeds the differential value
set and the minimum collector temperature set, the controller
switches the solar pump on. The solar cylinder is charging.
The differential value can be defined separately for two con-
nected solar cylinders.
8.12.2 Defining the switch-off differential for solar
charging
Menu → Installer level → System configuration → [Solar
cylinder 1 ----] → Switch-off diff.
– This function allows you to define a differential value
for stopping solar charging. The temperature difference
is measured between the lower cylinder temperature
sensor and the collector temperature sensor.
If the temperature difference falls below the differential value
that is set, the controller switches the solar pump off. The
solar cylinder is no longer charged. The off temperature dif-
ferential value must be at least 1 K less than the set on tem-
perature differential value.
8.12.3 Defining the maximum temperature for
solar cylinder
Menu → Installer level → System configuration → [Solar
cylinder 1 ----] → Maximum temperature
– This function allows you to define a maximum value as a
limit for the solar cylinder temperature, in order to guar-
antee the highest possible yield from the solar cylinder
heating, but also to ensure protection against calcifica-
tion.
If the maximum temperature set on the bottom cylinder tem-
perature sensor is exceeded, the controller switches the
solar pump off. Solar charging is only enabled again once
the temperature at the bottom cylinder temperature sensor
has fallen by between 1.5 K and 9 K, depending on the max-
imum temperature. The maximum temperature set must not
exceed the maximum permissible cylinder water temperature
of the cylinder that is used.
8.12.4 Reading the value for the bottom cylinder
temperature sensor
Menu → Installer level → System configuration → [Solar
cylinder 1 ----] → Cyl. temp.: Bottom
– You can use this function to read the current measured
value for the bottom cylinder temperature sensor.
