Grundfos ALPHA Installation And Operating Instructions Manual page 15

9.3.3 Constant pressure (zone valve)
In the constant-pressure (zone valve) mode the pump runs at
constant pressure which means the head (pressure difference) is
kept constant, irrespective of the actual number of opened zones.
The pump performance follows the selected constant-pressure
curve. This control mode is especially suitable for underfloor
heating and applications where the pump is used to supply a
common header for multiple zone valves. The head across each
zone will remain constant independent of how many zones request
heat, thus a constant flow in each zone will be maintained,
independent of other zones. The selection of the constant-pressure
setting depends on the characteristics of the zones in the heating
system and the actual heat demand.
H
Constant pressure
Related information
9.1 Operating panel
10.8 Settings according to system type
9.3.4 Constant pressure (zone valve), AUTOADAPT
With the constant pressure (zone valve) AUTOADAPT setting, the
pump analyses the heating system and over time selects the best
constant-pressure setpoint for the given operating conditions. It
continuously optimizes the position of the constant-pressure curve
via three steps:
1. The pump analyses the heat demand patterns of the heating
system.
2. AUTOADAPT verifies whether the pump pressure is too high,
too low or suitable.
3. The pump adjusts the setpoint and chooses the best suitable
constant-pressure curve from the AUTOADAPT range. The
pump will continue this cycle as long as it is running. See the
figure below.
H
Q
Pos. Description
1 Constant-pressure curve
2 Setpoint
3 AUTOADAPT performance range
If the power supply fails or is disconnected, the pump stores the
AUTOADAPT setting in an internal memory and resumes the
automatic adjustment when power supply has been restored.
Related information
9.1 Operating panel
3
1
2
Q
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