Viessmann Vitotronic 11 CC1E, Installation And Service Instructions Manual

Page: 101 / 120

101
20 A1
A
B
20
close close close
N L
K
1 2 n
Fig. 37
sÖ A1 Closing of mixers
A
Contactor relay, part no. 7814 681
B Downstream heating circuit controller, switching
contact closed:
Signal for mixer CLOSE
Multi boiler system
■ Plug sÖ A1 of the Vitotronic is used as a switching
contact for the Therm-Control.
■ Required parameter: "0D:1" in the "Boiler" group
and "53:2" in the "General" group
K3
K1 K2
L1
N
PE
1 2 ... n
A
A1
sÖ
A1
sÖ
K1
N L1
K2
N L1
A
C
B
D
A
Fig. 38
sÖ A1 Closing of mixers
A
Contactor relay, part no. 7814 681
B Downstream heating circuit controller, switching
contact closed:
Signal for mixer CLOSE
C Power supply, 230 V/50 Hz
D
Junction box, on site
Boiler protection function: Raising the return temperature via shunt pump or/and 3-way mixing
valve
■
With shunt pump
For heating systems with distributor installed close to
the boiler
■
With 3-way mixing valve:
For heating systems where downstream heating cir-
cuits cannot be controlled, e.g. older systems or
commercial nurseries.
■
Conditions:
–
The boiler water flow rate must be able to be
reduced by at least 50 %.
–
With shunt pump:
Size the shunt pump to approx. 30 % of the total
throughput.
–
With 3-way mixing valve:
Size the boiler circuit pump at each boiler to
approx. 110 % of the total throughput.
■
Also affects the heating circuits.
Function
Single boiler systems and multi boiler systems
with shunt pump
■
Temperature sensors T1 and T2 capture the return
temperature at different test points.
■
The shunt pump is started via temperature sensor T2
if the factory-selected minimum return temperature
(specified by the coding card) is not being achieved.
■
The flow rate will be reduced via the mixers if the
minimum return temperature captured by tempera-
ture sensor T1 is not achieved despite return temper-
ature raising.
Single boiler systems with shunt pump and 3-way
mixing valve
■
Temperature sensors T1 and T2 capture the return
temperature at different test points.
■
The shunt pump is started via temperature sensor T2
if the factory-selected minimum return temperature
(specified by the coding card) is not being achieved.
■
The flow rate will be reduced via the 3-way mixing
valve if the minimum return temperature captured by
temperature sensor T1 is not achieved despite return
temperature raising.
Function description
Boiler water temperature control
(cont.)
5863679
Functions