Buderus Logamax plus GB162 Technical Manual page 61

Logamax plus GB162-45
Δp [mbar ]
700
600
500
400
300
200
100
0
0 400 800
Fig. 55 Residual head GB162-45 with integral pump
UPM 15-70 2W
a Maximum modulation in output-dependent operation
with setting 0 at the RC35 programming unit
( tab. 25, page 64)
b Minimum modulation in output-dependent operation
with setting 0 at the RC35 programming unit
( tab. 25, page 64)
Δp
Residual head
V
Flow rate
1 to 4 Residual head for differential pressure-dependent
operation with setting 1 to 4 at the RC35
programming unit (
Pump modulation Logamax plus
GB162-15/25/35/45 and GB162-25 T40S
The RC35 programming unit of the Energy Management
System (EMS) enables the heating circuit pump of the
Logamax plus GB162 up to 45 kW to be adjusted in line
with the system, so that it can be operated with different
residual heads Δp = constant or output-dependent
( fig. 52 to fig. 55).
Heating circuit pump
If, in the case of a narrow temperature spread (e.g.
40/30 °C underfloor heating system), the residual head of
the integral heating circuit pump is insufficient to
overcome the system pressure drop downstream, install a
second diverter pump externally. For this, use a low loss
header to provide hydraulic separation.
Residual head Logamax plus GB162-45 and
GB162-50/65/80/100 without integral heating
circuit pump
Logamax plus GB162-45 and GB162-50/65/80/100 are
supplied from the factory without integral heating circuit
pumps. This enables a flexible hydraulic connection.
6 720 645 821 (2010/09) – Logamax plus GB162
a
4
3
2
1
b
1200 1600 2000
V [m
3
/h]
6 720 642 463-42.1il
tab. 25, page 64)
A connection with a heating circuit pump or pump
assembly integrated into the appliance is recommended
for the following applications:
• When using a low loss header (e.g. with several
heating circuits, cascades or high system flow rates); in
this case, the pump should operate under
output-dependent control
• With a separate 3-way diverter valve for the GB162-45
and DHW heating as priority
• With a pump assembly directly downstream and 3-way
valve kit as well as DHW heating as priority for the
GB162-50/65
• Where there are additional demands for very quiet
operation, the use of differential pressure regulators for
each line with a setting of 100 mbar to 150 mbar is
recommended
For a heating circuit directly downstream, the differential
pressure-dependent heating circuit pumps
recommended by Buderus can be used. Set the pump to
Δp-v (variable). The recommended settings facilitate quiet
operation and maximum flow rate. The curves are shown
on the graphs in fig. 56 to fig. 63.
The maximum permissible flow rate for the various boilers
is as follows:
• GB162-45 = 2500 l/h
• GB162-50/65/80/100 = 5700 l/h
A line balancing valve may be required to limit the flow
rate.
Logamax plus GB162-45
Δp [mbar ]
350
300
250
200
150
100
50
0
0 500 1000
Fig. 56 Residual head GB162-45 for pump
Wilo Stratos 25/1-8
a Resulting pump pressure 6 m
b Resulting pump pressure 5 m
c Resulting pump pressure 4 m
Δp
Residual head
V Flow rate
System examples 6
a
b
c
1500 2000 2500
V [l/h]
6 720 642 463-70.1il
61