DAB MCE-11/P, Instruction For Installation And Maintenance, Page: 98 / 600

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6.5.9.3 Operation with general flow sensor
This applies both to single and multiple sensors.
Use of the flow sensor enables effective measurement of the flow and the possibility of operation in special
applications.
This setting enables use of a general pulse type flow sensor by setting the relative K-factor, i.e. the factor of
pulse/litre conversion, depending on the sensor and pipeline on which it is installed. This operating mode can
also be useful in the case of using a pre-defined sensor fitted on a pipe with a diameter not present in those
available on the FD page. The k-factor can also be used when fitting a pre-defined sensor, when the user
requires a precise calibration of the flow sensor; obviously a precise flow measurement device must be
available. The setting of k-factor is made in the page FK (see section 6.5.11).
On selection of a general sensor, the setting of FD is disabled automatically. The parameter disabled
message is displayed by means of an icon with a padlock.
6.5.10 FD: Pipeline diameter setting
Diameter in inches of the pipeline on which the flow sensor is installed. This can only be set if a pre-defined
flow sensor has been selected.
If FI has been set for manual entry of the flow sensor, or if operation without flow sensor has been selected,
the parameter FD is disabled. The parameter disabled message is displayed by means of an icon with a
padlock.
The setting range is between ½ '' and 24''.
The pipelines and flanges on which the flow sensor is fitted can be, according to diameter, of different types
and in different materials; the transit sections may therefore differ slightly. As calculations of the flow take
into account average conversion values to enable operation with all types of pipeline, this may cause a
marginal error in reading the flow rate. The value read may differ by a small percentage, but if the user
requires a more precise reading, the following procedure is possible: insert a test flow reading device on the
pipeline, set FI for manual setting, modify the k-factor until the inverter shows the same reading as the test
instrument; see section 6.5.11. The same considerations apply when using a pipeline with non-standard
section; therefore: either enter the section closest to the effective value and accept the error margin, or
change the setting of k-factor, if required with reference to Table 19.
CAUTION
:
incorrect settings of FD causes false flow reading with possible risk of shutdown.
6.5.11 FK: Pulse/litre conversion factor settings
This expresses the number of pulses related to transit of one litre of fluid; it is based on the sensor used and
section of the pipeline on which it is installed.
If a flow sensor is fitted with a pulse type output, FK must be set according to the instructions of the sensor
manufacturer.
If FI has been set for a specific sensor from the pre-defined series, or operation without flow sensor has
been selected, the parameter is disabled. The parameter disabled message is displayed by means of an
icon with a padlock.
The setting range is between 0.01 and 320.00 pulses/litre. The parameter is applied by pressing SET or
MODE. The flow values found, but setting the pipeline diameter FD may differ slightly from the effective flow
measured due to the average conversion factor used in calculations, as explained in section
6.5.10
, and KF
may also be used with one of the pre-defined sensors, both to operate with non-standard pipeline diameters
or to perform a calibration procedure.
Table 19 specifies the k-factor used by the inverter according to the pipeline diameter when using sensor
F3.00.