Grundfos NBE Series - 7.5.1 Proportional pressure; 7.5.2 Constant pressure

7.5.1 Proportional pressure
Pump variant Proportional pressure
NBE, NKE, NBSE, VLSE -
NBE, NKE, NBSE Series
2000; VLSE with Delta ρ sensor
●
The head of the pump is reduced at decreasing water demand and
increased at rising water demand. See the figure below.
This control mode is especially suitable in systems with relatively
large pressure losses in the distribution pipes. The head of the
pump increases proportionally to the flow in the system to
compensate for the large pressure losses in the distribution pipes.
The setpoint can be set with an accuracy of 4 inches (10 cm). The
head against a closed valve is half the setpoint. The setting range is
between 25 % and 90 % of maximum head.
For more information about settings, see section on proportional-
pressure setup.
H
Q
Hset
Hset
2
TM057909
Proportional pressure
Example:
• Factory-fitted differential-pressure sensor.
Δp
TM057880
Proportional pressure
Controller settings
For the recommended controller settings, see the section on the
controller.
7.5.2
Constant pressure
Pump variant Constant pressure
NBE, NKE, NBSE, VLSE ●
NBE, NKE, NBSE Series
2000; VLSE with Delta ρ sensor
●
We recommend this control mode if the pump is to deliver a
constant pressure, independently of the flow in the system. The
pump maintains a constant pressure independently of the flow rate.
H
Q
TM057901
Constant pressure
This control mode requires an external pressure sensor as shown in
the examples below. You can set the pressure sensor in the Assist
menu. See the section on assisted pump setup. The setting range
is between 12.5 % and 100 % of maximum head.
Example:
• One external pressure sensor
p
TM057881
p
TM057882
Controller settings
For recommended controller settings, see the section on the
controller.
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English (US)