Technical data

Functions
13
DME
3
Maximum capacity limitation
Maximum capacity limitation makes it possible to
reduce the maximum capacity (MAX. CAP).
It influences the functions in which the pump normally
operates at maximum capacity. Under normal
operating conditions, the pump cannot operate at a
capacity higher than the one stated in the display.
When pushing the maximum capacity button, the pump
operates at 100 %.
With the maximum capacity limitation function, a large
pump can be set to operate as a much smaller pump.
Together with the 1:800 capacity range, this function
allows the following:
1. To utilize the smooth and even dosing
characteristics of the pump at low capacities to
achieve
– improved chemical mixing
– improved dosing through long discharge lines
– improved dosing of high-viscosity liquids.
2. To improve the dosing of gas-containing liquids:
In a large pump, the displaced volume (1) is much
larger than the non-displaced volume (2).
Fig. 11 Anti-cavitation
3. To cover several needs with just one pump size.
4. To adapt the pump to a 4-20 mA signal control with
4 mA corresponding to 0 % and 20 mA to the set
maximum capacity.
This allows you to use a DME for dosing a very small
quantity of liquid without having to change the input
signal.
Example:
A DME 376 receives a 12 mA input signal from a
control instrument. According to the analog curve
(see page 11), this results in a 50 % output and a
capacity of 188 l/h.
A new situation occurs where it is only necessary to
dose 47 l/h: The maximum capacity limitation is set to
94 l/h. The pump is still receiving a 12 mA signal
resulting in a 50 % output and a capacity of 47 l/h.
Fig. 12 Maximum capacity limitation
The maximum capacity limitation also reduces the
pump speed in timer-based batch control, pulse-based
batch control and during calibration where the pump
usually operates at maximum capacity.
Calibration
After start-up, the dosing pumps can be calibrated for
the actual installation to ensure that the displayed
value (millilitres or litres) is correct. A calibration
program in the set-up menu facilitates calibration.
Counters
The pump can display non-resettable counters for:
• "Quantity":
Accumulated dosed quantity in litres or US gallons.
• "Strokes":
Accumulated number of dosing strokes.
•"Hours":
Accumulated number of operating hours (power on).
•"Power ON":
Accumulated number of times the mains supply has
been switched on.
TM04 8832 1513
11
22
Small pump
Large pump
TM04 8791 1313
0 2 4 6 8 10 12 14 16 18 20
[mA]
0
Q [l/h]
188
94
47
376