48 DKDHR
VI.GP.P1.02
Danfoss District Energy
Instructions
VX Solo II
12.0 Circulation pumps
Grundfos Pumpe ALPHA2 L
Substation start-up / pump
Do not start the pump until the system has been filled with liquid
and vented. The required minimum inlet pressure must be available
at the pump inlet. See Grundfos instructions for the pump.
The heating system can be vented via an air escape valve installed
above the pump.
The pump is self-venting. It need not be vented before start-up.
Air in the pump may cause noise, This noise ceases after a few minu-
tes running.
Please note
, that the system cannot be vented through the pump
Please note
, that the pump must not run dry.
Pump setting
The pump is factory-set to start on the highest proportional-pres-
sure curve PP2. This setting is suitable for a large majority of all
single-family houses
In this pump setting the pump performance and consequently the
power consumption is adjusted according to hte heat demand in
the system.
Grundfos Alpha2 L has seven optional settings, which can be select-
ed with the push-button.
Enclosed photo shows the recommended and alternative pump set-
tings for system types.
For further information about pump settings please refer to the en-
closed Grundfos Instructions.
ALPHA2 L,
Installation and operating instructions
Summer operation
The circulation pump for heating is automatically switched off in pe-
riods without heat demand. To prevent the pump from blocking in
periods without heat demand, the controller automatically switches
on the pump for some minutes every third day. In this period the
circulation pump should be set at the highest speed of rotation.
If the heating requirement increases the pump setting can be changed
by means of the selector switch.
For more information about venting of pump etc. please refer to en-
closed installation and operating instructions.
Recommended and alternative pump settings for system type.
Pos.
System type
Pump setting
Recommended
Alternative
A.
Floor heating
Lowest constant-pressure
curve (
CP1
)
Highest constant-pressure
curve (
CP2
)
B.
Two-pipe systems
Highest constant-pressure
curve (
PP2
)
Lowest constant-pressure
curve (
PP1
)
C.
One-pipe systems
Lowest constant-pressure
curve (
PP1
)
Highest constant-pressure
curve (
PP2
)
