External Forced-Control Signals; Start/Stop Input; Digital Input; External Setpoint Signal - Grundfos LME Series Installation And Operating Instructions Manual

• The max. curve can be adjusted within the range from maxi-
mum performance (100%) to min. curve.
• The min. curve can be adjusted within the range from max.
curve to 12% of maximum performance. The pump has been
factory-set to 24% of maximum performance.
• The operating range lies between the min. and max. curves.

6. External forced-control signals

The pump has inputs for external signals for the forced-control
functions:
• Start/stop of pump.
• Digital function.

6.1 Start/stop input

Functional diagram: Start/stop input:
Start/stop (terminals 2 and 3)
H
H

6.2 Digital input

By means of the R100, one of the following functions can be se-
lected for the digital input:
• Min. curve.
• Max. curve.
Functional diagram: Input for digital function:
Digital function
(terminals 1 and 9 – single-phase pumps)
(terminals 1 and 3 – three-phase pumps)
H
H
H

7. External setpoint signal

By connecting an analog signal transmitter to the input for the
setpoint signal (terminal 4), it is possible to remote-set the set-
point.
The actual external signal (0-5 V (three-phase pumps only),
0-10 V, 0-20 mA, 4-20 mA) must be selected via the R100, see
section 5.3.3 Selection of external setpoint signal.
If uncontrolled operation is selected by means of the R100, the
pump can be controlled by any controller.
16
Normal duty
Q
Stop
Q
Normal duty
Q
Min. curve
Q
Max. curve
Q
In controlled-operation mode, the setpoint can be set externally
within the range from the lower value of the sensor measuring
range to the setpoint set on the pump or by means of the R100,
fig. 28.
Fig. 28
Control
Parameter
Upper value of sensor measuring range
Setpoint set on pump or with the R100
Lower value of sensor measuring range
0
5 V (three-phase pumps only)
0
10 V
0
20 mA
4
20 mA
Example: At a lower differential-pressure sensor value of 0 m, a
setpoint set of 20 m and an external setpoint of 80%, the actual
setpoint will be as follows:
H = (H - H ) x %
actual set lower external setpoint
= (20 - 0) x 80% + 0
= 16 m
In uncontrolled-operation mode, the setpoint can be set exter-
nally within the range from the min. curve to the setpoint set on
the pump or by means of the R100, fig. 29.
Fig. 29
%
Max. curve
Setpoint set on pump or with the R100
Min. curve
0
5 V (three-phase pumps only)
0
10 V
0
20 mA
4
20 mA

8. Bus signal

The pump enables serial communication via an RS-485 input.
The communication is carried out according to the GRUNDFOS
bus protocol, GENIbus protocol, and enables connection to a
building management system or another external control system.
Via the bus signal, it is possible to remote-set pump operating pa-
rameters, like setpoint, operating mode, etc. At the same time,
the pump can provide status information about important parame-
ters, like actual value of control parameter, input power, fault indi-
cations, etc.
Contact GRUNDFOS for further details.
Note: If a bus signal is used, the number of settings available via
the R100 will be reduced.
+ H
lower