Operating Modes; Manual; Pulse - Grundfos DME Serie Instrucciones De Instalación Y Funcionamiento

5.9 Operating modes

The displayed l and ml values are only
reliable if the pump has been calibrated to
Note
the actual installation, see section
7. Calibration.
The pump can run in five different operating modes:
•

Manual

•

Pulse

• Analog
• Timer (internal batch control)
• Batch (external batch control)
See description in the following sections.
5.10 Manual
The pump is dosing as constantly and evenly as
possible, without any external signals.
Set the quantity to be dosed in l/h or ml/h. The pump
automatically changes between the measuring units.
Setting range:
DME 60: 75 ml/h - 60 l/h
DME 150: 200 ml/h - 150 l/h
DME 375: 500 ml/h - 375 l/h
DME 940: 1200 ml/h - 940 l/h
Set value
Fig. 7
5.11 Pulse
The pump is dosing according to an external pulse
signal, i.e. a water meter with pulse output or a
controller.
Set the quantity to be dosed per pulse in ml/pulse.
The pump adjusts its capacity according to two
factors:
• Frequency of external pulses.
• The set quantity per pulse.
The pump measures the time between two pulses
and then calculates the speed giving the capacity
required (set quantity per pulse multiplied by the
pulse frequency).
The pump does not start until it has received the
second pulse, and thus it delivers a constant flow as
in the case of "manual" control. The pump calculates
a speed for each pulse received.
The pump stops
• when the time between two pulses is three times
longer than the time between the two previous
pulses, or
• if the time between two pulses exceeds 2
minutes.
The pump will operate at the latest calculated speed
until one of the two cases occurs.
The pump stops at the point reached in its duty cycle
and starts at this point again having received two
new pulses.
Setting range:
DME 60: 0.000625 ml/pulse - 120 ml/pulse
DME 150: 0.00156 ml/pulse - 300 ml/pulse
DME 375: 0.00392 ml/pulse - 750 ml/pulse
DME 940: 0.00980 ml/pulse - 1880 ml/pulse
Set quantity in
ml/pulse
Actual capacity in
ml/h or l/h
Fig. 8
If the set quantity per pulse multiplied by the pulse
frequency exceeds the pump capacity, the pump will
run at maximum capacity. Excess pulses will be
ignored and "MAX. FLOW" will appear in the display.
21