Viessmann VITOTRONIC 200 Installation And Service Instructions Manual page 77

Vitotronic 200 and 300-K Installation and Service
Cascade Control
Examples of the various control strategies
System with 2 Vitodens 200-W.
Condensing strategy (code "3C:0")
Starting
Shutdown
(continued)
Function Description, Vitotronic 300-K
Condensing strategy
H It is the aim of the condensing strategy to operate
as many boilers as possible at the lowest output level.
Benefits
H Optimum utilisation of condensing effect.
H Long burner runtimes
Starting criterion
H Boilers are started via an output statement
(code "3D:1").
H An additional boiler will start when the currently
required output can also be achieved by the currently
active boilers plus the next boiler in the boiler sequence
(see page 87).
Shutdown criterion
H The boilers are shut down via a shutdown integral.
The shutdown criterion is met when the shutdown
integral exceeds a limit set via coding address "46"
and the boiler started last will be shut down.
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