Grundfos AR Serie Montage- Und Betriebsanleitung Seite 19

8.6.5 Current signal control 0-20 mA / 4-20 mA
For controlling the dosing pump via an external current
signal of 0-20 mA (4-20 mA)
0-20mA
Run
Fig. 23 Input signal: 0-20 mA
4-20mA
Run
Fig. 24 Input signal: 4-20 mA
• The stroke frequency is proportional to a current input signal
of 0-20 mA (4-20 mA).
• Above 19.8 mA, the pump runs in continuous operation at
maximum stroke frequency.
• Below 0.2 (4.2) mA, the pump switches off.
The pump must be started first in this operating
mode (LED lights up green, "Run" appears in the
Note
display).
• Use the "Start/Stop" button to start or stop the pump.
4-20 mA current signal control
If the current input signal falls below 2 mA, the error relay is
switched, as an error has probably occurred at the signal source
or on the cable.
• The error signal relay switches on, the LED flashes red.
• "4-20 mA" and "ERROR" flash in the display.
4-20mA
Run
ERROR
Fig. 25 Display: current input signal < 2 mA
Analog
0
1/min
Analog
0
1/min
Analog
0
1/min
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