Plus Gb162 - Buderus Logamax plus GB162 Technical Manual

6 System examples
6.2.4 Heating circuit pumps for the Logamax plus GB162
Residual head Logamax plus GB162-15/25/35/45
and GB162-25 T40S
The residual head of the internal heating circuit pump
results from the differential between the pump pressure
and the pressure drop of the heat exchanger inside the
gas condensing boiler. It characterises the maximum
pressure that can be overcome by the heating circuit
pump in the heating circuit (available pump pressure).
The internal (integral) heating circuit pump of the
Logamax plus GB162 gas condensing boilers is
adequately sized for typical applications. The available
residual head can be checked in the graphs in fig. 52 to
fig. 54. In these graphs, the 3-way diverter valve that is
integrated into the gas condensing boiler has been taken
into consideration.
A high efficiency pump is available as an accessory for the
Logamax plus GB162-45 and can be installed inside the
boiler ( fig. 55).
Logamax plus GB162-15
Δp [mbar ]
300
4
250
3
200
150
100
50
0
0 200 400
Fig. 52 Residual head GB162-15
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 (
60
a
2
1
b
600 800 1000
V [m
3
/h]
6 720 642 463-39.1il
tab. 25, page 64)
Logamax plus GB162-25 and GB162-25 T40S
Δp [mbar ]
400
350
4
300
3
250
2
200
150
100
50
0
0 200 400
Fig. 53 Residual head GB162-25 and
GB162-25 T40S
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 (
Logamax plus GB162-35
Δp [mbar ]
500
450
400
350
300
250
200
150
100
50
0
0 200 400 600 800 1000 1200 1400 1600 1800
Fig. 54 Residual head GB162-35
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 (
6 720 645 821 (2010/09) – Logamax plus GB162
a
1
b
600 800 1000 1200 1400
V [m
3
/h]
6 720 642 463-40.1il
tab. 25, page 64)
4
3
2
1
a
b
V [m
3
6 720 642 463-41.1il
tab. 25, page 64)
/h]