Wiring
Proline Promag 55 FOUNDATION Fieldbus
48
Hauser
4.5
Potential equalization
#
Warning!
The potential equalization has to involved the measuring system.
Proper measurement is only ensured when the medium and the sensor have the same electrical
potential. Most Promag sensors have a reference electrode installed as standard, which guarantees
the required potential equalization.
The following must also be taken into account for potential equalization:
• Company-internal grounding guidelines
• Operating conditions such as material/grounding of piping etc. (see table)
4.5.1
Potential equalization, Promag S
• Reference electrode is standard for electrode material 1.4435/316L, Alloy C-22, tantalum,
titanium Gr. 2, Duplex 1.4462, tungsten carbide coating (for electrodes made of 1.4435)
• Reference electrode is optional for electrode made of platinum
• Reference electrode not present in measuring tubes with a natural rubber lining in conjunction
with brush electrodes.
"
Caution!
• For sensors without reference electrodes or without metal process connections, carry out
potential equalization as per the instructions for special cases
48. These special measures
are particularly important when standard grounding measures cannot be applied or extreme
equalizing currents are expected.
• Sensors with brush electrodes do not have a reference electrode. For this reason, ground disks
need to be installed in some cases to ensure sufficient potential equalization to the fluid. This
applies in particular to isolating lined pipes which are not grounded
4.5.2
Potential equalization, Promag H
No reference electrode available!
The metallic process connection always establishes an electrical connection to the fluid.
"
Caution!
When using process connections made of plastic, potential equalization must be guaranteed through
the use of grounding rings
28.
The necessary grounding rings may be ordered separately as an accessory from Hauser
(
79).
4.5.3
Connection examples for potential equalization
Standard case
Operating conditions
Potential equalization
When using the measuring device in:
• metallic, grounded piping
Potential equalization is carried out via the ground terminal of
the transmitter.
!
Note!
For installation in metal pipes, it is advisable to connect the
ground terminal of the transmitter housing to the piping.
A0011892
Fig. 33:
Via the transmitter's ground terminal
Содержание Proline Promag 55
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