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•
Linear with Stop
In the input signal range from 20 to 100 %, the
setpoint is influenced linearly.
If the input signal is below 10 %, the pump
changes to operating mode Stop.
If the input signal is increased above 15 %, the
operating mode is changed back to Normal. See
fig. 25.
Setpoint influence [%]
100
0
0
20
0.5
0
0
0
4
-50
Normal
Stop
Fig. 25
Linear with Stop
12.11 "Stop function" (Low-flow stop
function)
You can set the "Low-flow stop function" to these
values:
•
Not active
•
Energy-optimal mode
•
High-comfort mode
•
"User-defined mode" (Customised operating
mode).
When the low-flow stop function is active, the flow
rate is monitored. If the flow rate becomes lower than
the set minimum flow rate (Q
from continuous operation at constant pressure to
start-stop operation and stops if the flow rate
reaches zero.
The advantages of enabling the "Low-flow stop
function" are the following:
•
no unnecessary heating of the pumped liquid
•
reduced wear of the shaft seals
•
reduced noise from operation.
External
100 %
3.5 V
input
5 V
10 V
20 mA
20 mA
204 C
), the pump changes
min
The disadvantages of enabling the "Low-flow stop
function" may be the following:
•
The delivered pressure is not completely
constant as it fluctuates between the start and
stop pressures.
•
The frequent starts/stops of the pump may in
some applications cause acoustic noise.
The impact of the above disadvantages very much
depends on the setting selected for the stop function.
The High-comfort mode setting minimises pressure
fluctuations and acoustic noise.
Select Energy-optimal mode if the main priority is to
reduce the energy consumption as much as
possible.
Possible settings of the stop function:
•
Energy-optimal mode
The pump automatically adjusts the parameters
for the stop function so that the energy
consumption during the start-stop operation
period is minimised.
In this case, the stop function uses the
factory-set values of the minimum flowrate
(Q
) and other internal parameters. See fig.
min1
26.
•
High-comfort mode:
The pump automatically adjusts the parameters
for the stop function so that the disturbances
during the start-stop operation period are
minimised.
In this case, the stop function uses the
factory-set values of the minimum flowrate
(Q
) and other internal parameters. See fig.
min2
26.
•
"User-defined mode" (Customised operating
mode):
The pump uses the parameters set for ΔH and
minimum flow rate (Q
stop function. See fig. 26.
H
Stop pressure
H
Start pressure
Q
min2
Q
Fig. 26
Difference between start and stop
pressures (ΔH) and minimum flow rate
respectively for the
min3)
Q
Q
min1
min3
21
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