Viessmann VITOTRON 100 Installation And Service Instructions Manual page 15

Vitotron 100 Electric Boiler Installation/Service
Winter Mode
(Heating Mode)
To use the outdoor compensation option refer to outdoor
compensation graphs on page 14. The outlet temperature
is adjusted depending on the outdoor temperature.
For example, if it's cold, the outlet temperature should
increase, but if outdoor temperature is warmer, the
outlet temperature should be adjusted lower. Outdoor
compensation option is based on heating curves (see
"Advanced Settings").
User can choose from one of the 9 curves available,
declaring the desired thermal efficiency of the electric
boiler.
One method of selecting the correct curve is as follows.
The first step is to determine the temperature on the
horizontal axis (outside temperature from 0°F to 70°F),
which at the present time most frequently occurs, for
example 30°F.
Then run in a straight line up to the height on the value
of the temperature on the vertical axis which we want to
obtain in the hydronic system. In our example, at 30°F
outside the building we want to have 115°F for the
heating (see the diagram on page 14), so we get exactly
the heating curve defined as 4. If the intersection point of
selected temperatures is not placed on the curve, we
choose the closest. For example, 30°F outdoor
temperature, and the desired 110°F for hydronic system
can lead to a selection of curve 3 or 4. It should be
checked periodically, whether the choice was correct,
if not - another curve should be used.
The heating curve offset
If in wide range of outdoor temperatures the electric boiler
is not able to maintain the desired indoor temperature (it's
too cold or too warm), the heating curve chosen before
should be shifted (offset in range -9°F to +9°F available
in options on control panel). If the indoor temperature is
too warm - the heating curve should be shifted down and
vice versa (refer to the diagram on page 14).
(continued)
Special start-up procedure (when the system is filled with
an antifreeze solution)
A flow rate reading error may occur if you start-up the
unit at low ambient temperature. This error may occur
because the physical properties of antifreeze solution.
If the
opened you have to close OP and TT contacts which will
automatically start the special start-up procedure.
As a result, the medium will be warmed up to temperature
that enable you to read the flow rate correctly.
The duration of procedure depends on both the installation
capacity and the temperature inside the installation.
When a control panel display shows selected parameters
alternately and marks („-", „--", „---") it means that
the procedure is started. The procedure will close
automatically and the unit will start normal operation once
the minimal flow rate is reached.
Instructions for the User
indicator flickers and the cut-off valves are
15