Lutz-Jesco MAGDOS LA, Operating Instructions Manual

Page: 29 / 44

Operation
Operating modes
29
© Lutz-Jesco GmbH 2017
Subject to technical changes.
170502
BA-10010-02-V01
Solenoid-diaphragm dosing pump
MAGDOS LA / LD
Operating instructions
The number of pulse signals required for a dosing stroke is displayed on
the dosing pump display for values below 100%.
Fig. 28:
Int Start - +
50% (2)
Number of pulse signals required (here: 2)
Examples for transmission / reduction
Number of pulses Setting Dosing strokes
4 25% 1
2 50% 1
1 100% 1
2 100% 2
4 125% 5
1 1000% 10
Table 25: Examples for transmission / reduction of pulse signals
With sequences consisting of successive pulses, it is necessary to ensure
that given specific settings, the pulses are not always followed by the
number of dosing strokes which correspond to the pulses. This is due to
the circumstance that only one whole dosing stroke is performed, and not
e.g. half or a quarter of a dosing stroke. Depending on the transmission or
reduction factor and the number of pulses, however, there is a possibility
of uneven results with "pending" pulse signals. In theses cases, the
required number of dosing strokes is only achieved after a number of
pulse cycles.
Examples:
The dosing pump receives pulses with a reduction factor of 30%. For the
first stroke, it requires 4 pulses in this setting (4 x 30% = 120%), as 3
pulses (3 x 30% = 90%) are insufficient for one dosing stroke (= 100%).
However, the second dosing stroke is executed after just 3 more pulses,
as the stroke buffer of the dosing pump still has 20% pending from the
first 4 pulses (120% - 100% = 20%) and this is added to the 3 pulses
(90% + 20% = 110%). The third dosing stroke also only requires 3
additional pulses (90% + 10% = 100%). A further 4 pulses are then
required for the fourth dosing stroke.
If pulses are transferred to the dosing pump with a transmission factor of
125%, a dosing stroke is executed for each of the first 3 pulses. With the
4th pulse, it executes 2 dosing strokes (3x 25% pending from the first 3
125% = 200%).
The dosing pump has a dynamic stroke buffer which includes the interval
between the pulses in the calculation and adjusts the distribution of the
dosing strokes accordingly.
11.2.2.4 Calculating the transmission factor
The dosing pump MAGDOS LD has a defined stroke volume per dosing
stroke. If a certain dosing quantity is required per pulse, the correspond-
ing transmission factor can be calculated for the external operating
mode.
i You can find a simple means of performing the necessary
calculations on the Lutz-Jesco GmbH homepage. To do so,
click on the following link or enter it in your browser:
http://www.lutz-jesco.com/en/online-help
If you have no Internet connection, you can also perform the calculation
yourself.
The following parameters are required for this:
n
required dosing quantity in ml/pulse
n
delivery capacity of the dosing pump in ml/stroke
The delivery capacity of the dosing pump can be taken from in the
technical data and the delivery characteristic curves (see “delivery
capacity data” on page 13 and “delivery characteristic curves” on page
46). Intermediate values can be interpolated.
Calculate the value using the following formula:
required dosing quantity per pulse x 100%
delivery capacity per stroke
1 ml/pulse x 100
0,63 ml/stroke
= 159 %
required dosing quantity x pulse sequence of water meter
delivery capacity per stroke x 10
1000 x 1
0,63 x 10
= 159 %
dosing quantity in ml/m³ x nominal size of the water meter in m³/h
delivery capacity per stroke in ml/stroke
1000 ml/m³ x 5 m³/h
0,63 ml/stroke
= 7937 strokes/h
Example: With a MAGDOS LD 6, 1 ml should be proportionally dosed per
pulse. The stroke volume at 4 bar is 0.63 ml.
The factor to be set is calculated as follows:
required dosing quantity per pulse x 100%
delivery capacity per stroke
1 ml/pulse x 100
0,63 ml/stroke
= 159 %
required dosing quantity x pulse sequence of water meter
delivery capacity per stroke x 10
1000 x 1
0,63 x 10
= 159 %
dosing quantity in ml/m³ x nominal size of the water meter in m³/h
delivery capacity per stroke in ml/stroke
1000 ml/m³ x 5 m³/h
0,63 ml/stroke
= 7937 strokes/h
In this example, the pump would execute 159 strokes for 100 incoming
pulses.
i Note that the stroke frequency of the dosing pump is
restricted. For the MAGDOS LD 6, the max. stroke frequency is
approx. 180 strokes/min. Any additional incoming strokes are
not processed.
For this example, this means that the dosing pump can
process a maximum of 113 pulses/min (180/1.59).
11.2.2.5 Starting the dosing pump
Precondition for action:
ü
The dosing pump has been connected in accordance with the
chapter “Pulse input (only LD)” on page 24.
1.
Press Start .
2.
Supply pulses to the pulse input of the dosing pump.
ü
Dosing pump has started.
11.2.2.6 Stopping the dosing pump
è
Stop the incoming pulses or press Stop.
ü
Dosing pump has stopped.