6.4 Connection on the heating side
Connection on the heating side without return temperature limit
According to DIN 4753, the water in the DHW cylinder may be
heated to approx. 95 °C.
To ensure that the DHW temperature never exceeds 95 °C, install a
control unit to regulate the heat supply in accordance with the follow-
ing circuit diagrams.
With the installation according to the diagrams on page 40
and 42, the circulation pump for the DHW cylinder is switched by
the temperature controller. The spring-loaded check valve prevents
continued heating of the DHW cylinder due to natural circulation.
A water temperature controller may also be used instead of the tem-
perature controller (see diagrams on page 42).
When heating water flow temperatures exceed 110 °C, also fit a
type-tested high limit safety cut-out. For this, the TR/HLSC combina-
tion device with 2 separate thermostatic systems (temperature limiter
and high limit safety cut-out) is used (see diagrams on page 42).
Systems that already incorporate a high limit safety cut-out for limit-
ing the temperature of the heating medium to 110 °C, (e.g. in the
boiler), require no additional high limit safety cut-out in the DHW cyl-
inder.
Cylinder banks
For cylinder banks, it is sufficient to install a temperature controller in
only one of the cylinders.
If individual cylinders in a cylinder bank need to be controlled sepa-
rately, group the cylinders into several cylinder banks or install them
as individual cylinders.
■ Vitocell 300-H:
With cylinder banks, make the connections on the heating water
side and arrange the temperature controller and high limit safety
cut-out (if required) as shown in the diagrams from page 41.
■ Vitocell 100-V and Vitocell 300-V:
The cylinder bank is controlled by one temperature controller. The
individual cylinders in a cylinder bank therefore cannot be control-
led separately. Install the temperature controller in the last cylinder
as seen from the heating water flow (see diagrams on page 42).
Vitocell 100-H and Vitocell 300-H
130, 160 and 200 l capacity
A
Temperature sensor/temperature controller and high limit safety
cut-out (if required)
B
Air vent valve
C
Heating water return
D
Heating water flow
E
Circulation pump
F
Spring-loaded check valve
G
Vitocell 100-H or Vitocell 300-H
350 and 500 l capacity
A
Temperature sensor/temperature controller and high limit safety
cut-out (if required)
B
Air vent valve
C
Heating water return
D
Heating water flow
E
Circulation pump
F
Spring-loaded check valve
G
Vitocell 100-H or Vitocell 300-H
Installation — DHW cylinders
(cont.)
40
VIESMANN
DHW heating
6
5414646