Grundfos Medium UPM Series Data Booklet page 15

Medium UPM
Advantages of AUTO
ADAPT
• Easy installation
• Automatic setting
• Demand-controlled operations
• Optimum comfort
• Energy savings
• Reduced CO emissions.
2
Constant pressure at all load conditions is essential for
how well the thermostatic valves can control the heat
emission from the radiators. It is a well-known fact that
optimum pump control in a two-pipe heating system
with thermostatic radiator valves is best obtained by
controlling pump pressure on a proportional pressure
curve. In systems as underfloor heating or one-pipe
systems it might be better to use Constant Pressure
control. However, predicting the best position in real-
life applications is rather difficult, because the optimum
position depends on correlated factors such as the
size of the heating system, the boiler type, the load
condition, etc. This is where AUTO
ensure that the pump is controlled in an optimum
manner.
The AUTO algorithm
ADAPT
The objective of the AUTO
ADAPT
measure and analyse the heating system during
operation and adapt to the current heating pattern. The
system adapts to night vs. day operations, summer vs.
winter season, and heat losses or gains affecting room
temperature, for example, from radiators, walls and
windows, sun radiation, electrical equipment, and
people.
AUTO three-step task
ADAPT
Proportional or constant
pressure control
System
analyser
The
Fig. 13 AUTO three-step task
ADAPT
Basically, AUTO optimises the position of the
ADAPT
proportional or constant pressure curve via a three-
step task.
The "system analyser" analyses the heating system of
which the pump is a part. On the basis of the analysis,
AUTO verifies whether the pump pressure is too
ADAPT
high or too low or correct. The "curve selector" uses
this knowledge to select the optimum proportional-
pressure or constant-pressure curve for the pump. The
pump is controlled according to the selected
proportional-pressure or constant-pressure curve by
means of the "Proportional Pressure or Constant
Pressure control". The pump continues this cycle as
long as it is running.
steps in to
ADAPT
algorithm is to
Curve selector
Example
This example shows proportional pressure
AUTO .
ADAPT
Note: The Constant Pressure AUTO
acts accordingly just by utilising Constant Pressure
control, and not Proportional Pressure control as
shown in the example below.
The AUTO function can operate and adjust pump
ADAPT
speed according to duty point within a specific area.
Fig. 14 Proportional pressure AUTO
As default the AUTO
ADAPT
pump on the middle proportional pressure curve. By
use of an immediate acting PI-controlling function the
pump will adapt to the system on this proportional
pressure curve.
Note: The PI controller is set to eliminate any offset
within a time frame of 120 seconds.
H
Fig. 15 Proportional pressure control
function
ADAPT
Pump max. curve
operation area
ADAPT
is preset to operate the
Q
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