Frost Protection Function; Heating Curve Setting (Slope And Level); Flow Temperature Sensor; Cylinder Temperature Sensor - Viessmann VITODENS 050-W Technical Manual

Control unit
(cont.)

Frost protection function

■ The frost protection function will start when the outside tempera-
ture falls below approx. +1 °C.
With active frost protection, the heating circuit pump is switched on
and set to reduced flow temperature.
■ If the actual temperature in the DHW cylinder is < 5 °C, the DHW
cylinder is heated to 20 °C. If weather-compensated operation is
configured with external heating circuit hook-up, then the heating
circuit frost protection function is not active (if the contact is not
assigned). Frost protection for the heating circuit must be provided
on site.
■ The frost protection function will stop when the outside tempera-
ture exceeds approx. +3 °C.

Heating curve setting (slope and level)

The flow temperature of the heating circuit without mixer and the
flow temperature of the heating circuits with mixer (in conjunction
with the extension kit for one heating circuit with mixer) are control-
led in weather-compensated mode. The flow temperature of the heat
generator is therefore automatically regulated to between 0 and 40 K
above the currently required set flow temperature (delivered condi-
tion 8 K).
The flow temperature required to reach a specific room temperature
depends on the heating system and the thermal insulation of the
building to be heated.
Adjusting the heating curves matches the boiler water temperature
and the flow temperature to these conditions.
Heating curves:
The flow temperature is restricted at the upper end of the scale by
the temperature limiter and the maximum temperature set at the
electronic maximum temperature limiter.
The flow temperature of the heating circuits cannot exceed the flow
temperature of the heat generator.

Flow temperature sensor

The flow temperature sensor is connected to the HBMU heat man-
agement unit and installed in the appliance.
6

Cylinder temperature sensor

Standard delivery for:
Vitodens 050-W:
■ Part of the standard delivery of the connection set for DHW cylin-
ders below the boiler (120 or 150 l) (order separately)
■ Part of the standard delivery of the connection set for DHW cylin-
ders adjacent to the boiler (160 to 400 l) or alternative DHW cylin-
ders (order separately)
■ Cylinder temperature sensor (part no. ZK04671)
Required with on-site DHW cylinder
VIESMANN
52
Heating curve slope
90
80
70
60
50
40
30
20
20 15 10 5 0
Outside temperature in °C
Specification
Sensor type Viessmann NTC 10 kΩ at 25 °C
Permissible ambient temperature
– Operation 0 to +130 °C
– Storage and transport –20 to +70 °C
Specification
Cable length 3.75 m, fully wired
IP rating IP 32
Sensor type Viessmann NTC 10 kΩ at 25 °C
Permissible ambient temperature
– Operation 0 to +90 °C
– Storage and transport –20 to +70 °C
1.4
1.2
1.0
0.8
0.6
0.4
0.2
-5 -10 -15 -20 -25 -30
VITODENS