Grundfos ALPHA Installation And Operating Instructions Manual page 16

9.3.5 Proportional pressure (thermostatic radiator valve (TRV))
In the proportional-pressure (thermostatic radiator valve (TRV))
mode, the pump runs at proportional pressure, which means the
head (pressure) is reduced at falling heat demand and increased at
rising heat demand. The pump performance follows the selected
proportional-pressure curve. This control mode is especially
suitable for applications where the heat emitters are equipped with
a TRV which controls the flow depending on the room temperature.
At increased flow, the losses in the distribution system (pipes and
fittings) increase, hence the pumps increase the pressure to
compensate and vice versa, hereby maintaining an almost constant
differential pressure across the thermostatic radiator valve.
The proportional-pressure mode setpoint depends on the heating
system's characteristics and the actual heat demand.
H
2
Pos. Description
H
1
set
2 H × 0.40
set
Related information
10.8 Settings according to system type
16
1
Q
9.3.6 Proportional pressure (thermostatic radiator valve (TRV)),
AUTOADAPT
The thermostatic radiator valve (proportional pressure)
AUTOADAPT setting analyses the heating system and over time
selects the best proportional pressure setpoint under 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
seating.
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
proportional-pressure curve from the AUTOADAPT range. The
pump will continue this cycle as long as it is running. See the
figure below.
3
1
H
Pos. Description
1 Proportional-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.
2
Q