Grundfos alpha2 l User Manual

English (GB)
12
8. Setting the pump
8.1 Pump setting for system type
Fig. 10 Selection of pump setting for system type
Factory setting = highest proportional-pressure curve (PP2).
Recommended and alternative pump settings according to fig. 10:
Changing from recommended to alternative pump setting
Heating systems are "slow" systems that cannot be set to the
optimum operation within minutes or hours.
If the recommended pump setting does not give the desired
distribution of heat in the rooms of the house, change the pump
setting to the shown alternative.
Explanation to pump settings in relation to performance curves,
see section 11. Pump settings and pump performance.
8.2 Pump control
During operation, the pump head will be controlled according to
the principle "proportional-pressure control" (PP) or "constant-
pressure control" (CP).
In these control modes, the pump performance and consequently
the power consumption are adjusted according to the heat
demand in the system.
Proportional-pressure control
In this control mode, the differential pressure across the pump is
controlled according to the flow.
The proportional-pressure curves are indicated by PP1 and PP2
in the Q/H diagrams. See section 11. Pump settings and pump
performance.
Constant-pressure control
In this control mode, a constant differential pressure across the
pump is maintained, irrespective of the flow.
The constant-pressure curves are indicated by CP1 and CP2 and
are the horizontal performance curves in the Q/H diagrams.
See section 11. Pump settings and pump performance.
TM05 1921 4512
Pos. System type
Pump setting
Recommended Alternative
A Underfloor heating Lowest constant-pressure curve (CP1)* Highest constant-pressure curve (CP2)*
B Two-pipe systems Highest proportional-pressure curve (PP2)* Lowest proportional-pressure curve (PP1)*
C One-pipe systems Lowest proportional-pressure curve (PP1)* Highest proportional-pressure curve (PP2)*
D Domestic water Constant speed, speed I* Constant speed, speed II or III*
* See section 14.1 Guide to performance curves.
I
II
III
POWER
ON
I
I
I
II
I
P
O
WER
ON
I
II
III
POWER
ON
OK
(
OK
)
I
II
III
POWER
ON
I
II
I
I
I
P
O
WER
O
WER
O
R
ON
I
II
III
POWER
ON
OK
(
OK
)
I
II
III
POWER
ON
I
II
III
POWER
ON
I
II
III
P
O
WER
ON
OK
(
OK
)
I
II
III
POWER
ON
I
II
III
POWER
ON
I
II
I
I
I
P
O
WER
ER
O
N
OK
(
OK
)
A
B
C
D

Grundfos alpha2 l Specifications

General

Pump Type	Circulator Pump
Series	ALPHA2 L
Max Head	6 m
Voltage	230 V
Frequency	50/60 Hz
Temperature Range	2°C to 110°C
Material	Cast iron
Max Operating Pressure	10 bar
Installation Length	180 mm
Enclosure Class	IP42
Insulation Class	F
Weight	2.1 kg
Protection Class	Class I