2-Boiler System With Boiler Control And Heating Circuit Control - Buderus Logano GE315 Technical Manual

7 Systems
7.6

2-boiler system with boiler control and heating circuit control

FW
1
Fig. 36 System example for two Ecostream cast iron boilers; DHW heating with DHW cylinder; number and version
of the heating circuits dependent on the Logamatic control unit
DV Flue gas butterfly valve
FK Boiler water temperature sensor
FV Flow temperature sensor
FVS Strategy flow temperature sensor
FW DHW temperature sensor
HK Heating circuit
KR Check valve
PH Heating circuit pump
PS Cylinder primary pump
PZ DHW circulation pump
RK Return
SH Heating circuit actuator
VK Boiler flow
1 DHW cylinder (primary store system as option)
The circuit diagram is only a schematic
illustration!
For information on all system examples,
page 36.
Application area
• Ecostream cast iron boilers Logano GE315, GE515
and GE615
• Boiler control and heating circuit control (heating
circuits with actuators) with Logamatic 4211 or 4311
control unit
46
FVS
PZ
FK2
VK
KR
KR
PS
Logano (2)
6 720 646 864 (12/2010) – Technical guide Logano GE315, GE515 and GE615
DV2
FK1
RK VK
RK
Logano (1)
Function description
Both Ecostream cast iron boilers can be shut off
hydraulically. The boiler sequence can be controlled via
the multi boiler strategy module subject to load and time.
If the temperature at the strategy sensor FVS falls below
the set flow temperature, the Logano (1) lead boiler starts.
If the heat demand increases, the Logano (2) lag boiler is
automatically switched on and the flue gas butterfly valve
DV2 is opened. If the load falls, the switching processes
run in reverse order.
The Logamatic control unit safeguards the operating flow
temperature of both boilers. If the operating flow
temperature falls below the set value when the burner is
on, the control unit reduces the flow rate in the boiler flow
by overriding control of the heating circuit actuators SH
until the operating temperature has been reached.
To support this function, the circulation pumps remain off
until shortly before the operating flow temperature is
reached.
Special design information
• Distribute the total output between the boilers so each
has 50 %. If the output is distributed differently,
safeguard the flow rates using suitable measures
(sizing the pipework and/or balancing valves).
HK1 HK2
FV1 FV2
PH1 PH2
SH1 SH2
DV1
6 720 644 097-29.1il