Boiler Protection Function: Distribution Pump - Viessmann Vitotronic 11 CC1E Installation And Service Instructions Manual

Boiler water temperature control

Boiler protection function: Distribution pump

For heating systems with remote substation
■
( 20 m).
>
■ Conditions:
The heat transfer must be able to be reduced.
■ Also affects the heating circuits.
■ The distribution pump must be started by a higher
third party control unit if a boiler is enabled.
Size the distribution pump to approx. 110 % of the
■
total throughput.
■ With injection control:
For heating circuits that require heat as soon as a
heat demand is issued (e.g. air heaters).
Function
Multi boiler systems with distribution pump and low
pressure distributor
■ Temperature sensor T1 captures the return tempera-
ture.
The burner is ramped up to full load if the factory-
■
selected set temperature (specified by the coding
card) is not being achieved. The flow rate is reduced
via the mixer. The mixers are fully closed upon
demand.
■ If the set temperature is exceeded, the mixers are
opened. The flow rate is always increased to 100 %.
Multi boiler systems with distribution pump and injec-
tion control
■ Temperature sensor T1 captures the return tempera-
ture.
■ The burner is ramped up to full load if the factory-
selected set temperature (specified by the coding
card) is not being achieved. The flow rate is reduced
via the mixer. For this, the mixers are proportionally
or fully closed.
■ If the set temperature is exceeded, the mixers are
opened. The flow rate is always increased to 100 %.
Control sequence
Boiler goes cold
The burner is started if the boiler water temperature
falls 2 K below the set boiler water temperature. The
burner starts its own monitoring program.
Note
The burner start may be delayed by a few minutes,
depending on the number of auxiliary circuits and the
combustion type.
(cont.)
Connection in heating systems without LON
Multi boiler system
■ Plug A1 of the Vitotronic is used as a switching
sÖ
contact.
Required parameter: "0D:1" in the "Boiler" group
■
and "53:2" in the "General" group
L1
C
N
PE
A1
sÖ
N L1
K1
A
Fig. 41
sÖ A1 Closing of mixers
Contactor relay, part no. 7814 681
A
Downstream heating circuit controller, switching
B
contact closed:
Signal for mixer CLOSE
Power supply, 230 V/50 Hz
C
Junction box, on site
D
Boiler heats up
Single stage burner:
■
The burner is stopped if the boiler water temperature
rises 2 K above the set boiler water temperature.
■ Two-stage or modulating burner:
The burner is stopped if the boiler water temperature
rises above the set boiler water temperature by the
shutdown differential.
The shutdown differential is set at parameter "13" in
the "Boiler" group.
Function description
K1 K2
A1
sÖ
N L1
K3
K2
A
A
B
1
D
2 ... n
103