Grundfos TPE - Setpoint Influence and Operating Range; External Setpoint Influence Methods

English (GB)
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L2 = Distance [m] between heat exchanger and sensor.
General rules of thumb
If the controller is too slow-reacting, increase K
p
.
If the controller is hunting or unstable, dampen the system by
reducing K
p
or increasing T
i
.
10.12 Operating range
Set the operating range as follows:
• Set the min. speed within the range from fixed min. speed to
user-set max. speed.
• Set the max. speed within the range from user-set min. speed
to fixed max. speed.
The range between the user-set min. and max. speeds is the
operating range. See fig. 35.
Fig. 35 Example of min. and max. settings
10.13 Setpoint influence
10.13.1 External setpoint influence
It is possible to influence the setpoint by an external signal, either
via one of the analog inputs or, if an advanced functional module
is fitted, via one of the Pt100/1000 inputs.
If more than one input has been set up for setpoint influence, the
function will select the analog input with the lowest number, for
example "Analog input 2", and ignore the other inputs, for
example "Analog input 3" or "Pt100/1000 input 1".
Differential-temperature
control
K
p
T
i
-0.5 10 + 5L2
Flow control K
p
T
i
0.5 0.5
Constant-pressure control K
p
T
i
0.5 0.5
0.1 0.5
Level control K
p
T
i
-2.5 100
2.5 100
t
L2
t
t
t
L2
Q
p
p
L
L
Note
Speeds below 25 % may result in noise from the
shaft seal.
TM00 6785 5095
Note
Before the " Digital inputs " can be enabled, one of
the analog inputs or Pt100/1000 inputs must be
set to "
External setpoint function ".
See sections 10.5
Analog inputs and
10.6
Pt100/1000 inputs .
Max. speed (fixed)
User-set max. speed
Operating range
User-set min. speed
Min. speed (fixed)
24 %
12 %
0 %
67 %
100 % (110 %)