Technical data

130
Function description – Vitocontrol-S, VD2/CT3/CM2
Heating circuit control
Brief description
The control unit provides control
circuits for one high temperature
(boiler) circuit and two mixing valve
circuits.
The set supply temperature of every
heating circuit results from the outdoor
temperature, the set room temperature,
the operating mode and the heating
curve.
The supply temperature of the system
circuit corresponds to the common
system supply temperature.
The supply temperature of the mixing
valve circuits is regulated by the
stepped opening or closing of the
mixing valves.
The mixing motor control changes the
actuating and pause times subject to
the control difference
(control deviation).
Coding addresses which influence the
heating circuit control
A0 to F2
For a description, see the coding
overview.
Functions
The high temperature (boiler) circuit is
subject to the boiler water temperature
and its control range limits.
The heating circuit pump is the
controlling element. The mixing valve
circuit supply temperature is recorded
by the supply temperature sensor.
Time program
The control unit timer changes in
accordance with the times programmed
in the room heating and DHW heating
program between the heating with
normal room temperature and heating
with reduced room temperature
operating modes.
Every operating mode has its own set
level.
Outdoor temperature
A heating curve must be set up for
matching the control unit to the
building and the heating system.
The heating curve characteristics
determine the set boiler water
temperature subject to outdoor
temperature. An average outdoor
temperature (dampened) is used for
control purposes. This comprises the
actual and the adjusted outdoor
temperature.
5351 340 v1.4