Grundfos CUE Series Product Manual page 16

Functions
Constant pressure with stop function
The outlet pressure is kept constant at high flow rate.
On/off operation at low flow rate. See fig. 8.
H
set
Q Q
min. max.
Fig. 8 Constant pressure with stop function
The pump is controlled according to a constant pres-
sure measured after the pump. This means that the
pump offers a constant pressure in the Q-range of Q
to Q , represented by the horizontal line in the QH
max.
diagram.
Constant level
The liquid level is kept constant, independently of the
flow rate. See fig. 9.
Q Q
min max
Fig. 9 Constant level
The pump is controlled according to a constant liquid
level. This means that the pump offers a constant level
in the Q-range of Q
min.
parable line in the QH diagram.
The function is default an emptying function.
16
CUE
P
min
CUE
L
to Q , represented by the
max.
Constant level with stop function
The liquid level is kept constant at high flow rate. On/off
operation at low flow rate. See fig. 10.
Q Q
min max.
Fig. 10 Constant level with stop function
The pump is controlled according to a constant liquid
level. This means that the pump offers a constant level
in the Q-range of Q to Q
min. max.
parable line in the QH diagram.
The function is default an emptying function.
Constant flow rate
The flow rate is kept constant, independently of the
head. See fig. 11.
Q Q
min max
Fig. 11 Constant flow rate
The pump is controlled according to a constant flow
rate, represented by the vertical line in the QH diagram.
Grundfos CUE
CUE
L
, represented by the
CUE
Q