1-Boiler System With Unimat Ut-L Boiler: Boiler Circuit Control Unit With Hydraulic Separation - Bosch UT-L 1 Technical Manual

60 | System examples
9.7

1-boiler system with UNIMAT UT-L boiler: boiler circuit control unit with hydraulic separation

Fig. 41 System example with boiler circuit control unit and hydraulic separation (list of abbreviations
1)
[ ] Enabling (potential-free)
 Burner stage I
 Burner stage II or modulation
The circuit diagram is only a schematic
illustration! Information regarding all
system examples  page 47 ff.
AREA OF APPLICATION
• UNIMAT UT-L boiler
• boiler circuit control unit
– Maintaining the operating conditions
– Enabling of burner stages
• Hydraulic separation
• System structure in this form if a feed pump is
required, e.g. through sizing the heating circuit
pumps, or if several distributor stations are required,
or if the distributor stations are installed far apart
Brief description of the system
• Minimum return temperature controlled via a
separate actuator in the boiler circuit and a boiler
circuit pump as primary circuit pump
• 2-stage or modulating burner mode
• Control of heating circuit using CFB control unit or on-
site control unit
6 720 807 794 (2013/04)
SR
PK
FZ
VK RK
CFB 810
+ CME 930
HK
THV
FV
PH
SH
WH
Function description
The 3-way valve is actuated to control the return
temperature. The return temperature sensor measures
the boiler return temperature. If this falls below the set
value, the flow rate to the return is constantly restricted
by actuating the 3-way valve. If the return temperature
rises above the set value, the 3-way valve is reopened
and the flow rate to the heating circuit increases.
Special design information
• Allow for a low loss header.
• Switch the boiler circuit pump to constant mode or
set a run-on time of 60 minutes.
VV
VR
6 720 803 977-21.1itl

page 47)
UNIMAT