Operating Range; External Setpoint Function - Grundfos TPE2 Installation And Operating Instructions Manual

17.19 Operating range

Pump variant
TPE3, TPE3 D
TPE2, TPE2 D
Set the operating range as follows:
• Set the minimum speed within the range from fixed minimum
speed to user-set maximum speed.
• Set the maximum speed within the range from user-set
minimum speed to fixed maximum speed.
The range between the user-set minimum and maximum speeds
is the operating range. See fig. 59.
Speeds below 25 % may result in noise from the shaft seal.
100 %
Fixed maximum speed
67 % User-set maximum speed

"Operating range"

24 %
User-set minimum speed
13 % Fixed minimum speed
0 %
Fig. 59 Example of minimum and maximum settings
Factory setting
See section 35. Factory settings.

17.20 External setpoint function

Pump variant
TPE3, TPE3 D
TPE2, TPE2 D
You can 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.
Before you can enable the External setpoint function,
you must set one of the analog inputs or Pt100/1000
inputs to Setpoint influence.
See section 17.10 Analog inputs
17.12 Pt100/1000 inputs.
If more than one input has been set to Setpoint influence, the
function selects the analog input with the lowest number, for
example Setting of pump, and ignores the other inputs, for
example Analog input 3 or "Pt100/1000 input 1".
Operating range
●
●

External setpoint function

●
●
and
Example with constant pressure with linear influence
Actual setpoint: actual input signal x (setpoint - sensor min.) +
sensor min.
At a lower sensor value of 0 bar, a setpoint of 2 bar and an
external setpoint of 60 %, the actual setpoint is 0.06 x (2 - 0) + 0 =
1.2 bar.
[bar]
Sensor max.
"Setpoint"
2 100
Actual
1.2
"setpoint"
Sensor min.
0 0
0
0.5
0
0
0
4
-50
Fig. 60 Example of setpoint influence with sensor feedback
Example with constant curve with linear influence
Actual setpoint: actual input signal x (setpoint - user-set minimum
speed) + user-set minimum speed.
At a user-set minimum speed of 25 %, a setpoint of 85 % and an
external setpoint of 60 %, the actual setpoint is 0.60 x (85-25) +
25 = 61 %. See fig. 61.
In some cases, the maximum curve is limited to a lower speed.
See fig. 52.
Speed [%]
100
"Setpoint"
85
Actual
61
setpoint
User-set min.
25
speed
0
Actual input
0
signal, 60 %
0.5
0
0
0
4
-50
Fig. 61 Example of setpoint influence with constant curve
Factory setting
See section 35. Factory settings.
Actual External
100 %
input setpoint
3.5 V
5 V
signal, signal
10 V
60 %
20 mA
20 mA
204 C
Fixed
maximum
speed
External
100 %
setpoint
3.5 V
5 V
signal
10 V
20 mA
20 mA
204 C
43