Viessmann VITOTRONIC 200 Installation And Service Instructions Manual page 81

Vitotronic 200 and 300-K Installation and Service
Heating Circuit Control
Raising the reduced room temperature
During operation with reduced room temperature,
the reduced set room temperature can be automatically
raised subject to the outside temperature.
The temperature is raised in accordance with the selected
heating curve, but no higher than the set standard room
temperature.
The outside temperature limits for the start and end
of the temperature raising can be adjusted via coding
addresses "F8" and "F9".
Example using the settings in the factory set condition
Time in h
Legend
A Start of operation with standard room temperature
B Set boiler water or supply temperature in accordance
with the selected heating curve
C Set boiler water or supply temperature in
accordance with the selected coding address "FA":
122° F + 20% = 146° F (50° C + 20% = 60° C)
D Duration of operation with raised set boiler water or
supply temperature in accordance with coding address
"FB": 60 min.
Reducing the heat-up time
During the transition from operation with reduced room
temperature to operation with standard room temperature,
the boiler water or supply temperature will be raised in
accordance with the selected heating curve. The boiler
water or supply temperature increase can be automatically
raised.
The value and duration of the additional increase of the
set boiler water temperature or supply temperature is
adjusted in coding addresses "FA" and "FB".
(continued)
Upper control range limit
Electronic maximum limit
Setting range: 1 to 127º C
Changes via coding address "C6".
Note: The maximum limit is no replacement for the
Lower control range limit
Electronic minimum limit
Setting range: 1 to 127º C
Change via coding address "C5"
(operates only in standard mode).
Control sequence
Mixing valve circuit
The mixing valve motor will not be controlled within
the "neutral zone" (±1 K).
Supply temperature drops
(Set value −1 K)
The mixing valve motor receives the signal "Mixing valve
open". The signal duration lengthens with an increasing
control differential.
The duration of pauses reduces with an increasing control
differential.
Supply temperature rises
(Set value +1 K)
The mixing valve motor receives the signal "Mixing valve
closed". The signal duration lengthens with an increasing
control differential.
The duration of pauses reduces with an increasing control
differential.
Function Description, Vitotronic 300-K
underfloor heating system temperature limiter.
Temperature limiter for underfloor heating:
The temperature limiter switches the heating circuit
pump OFF if the set value has been exceeded. In
such cases, the supply temperature reduces only
slowly, i.e. it may be several hours before the
system restarts again automatically.
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