Endress+Hauser Proline Promag 50 - 4.3 Potential Equalisation

4 Wiring PROline Promag 50
56 Endress+Hauser
4.3 Potential equalisation
4.3.1 Standard case
Perfect measurement is only ensured when the medium and the sensor have the same
electrical potential. Most Promag sensors have a standard installed reference electrode
which guarantees the required connection. This usually means that additional potential
matching measures are unnecessary.
Promag W:
Reference electrode is standard
Promag P:
• Reference electrode is standard for electrode materials 1.4435, Alloy C-22 and
tantalum.
• Reference electrode is optional for electrode material Pt/Rh.
Promag H:
• No reference electrode. The metallic process connection provides a permanent
electrical connection to the fluid.
• If the process connections are made of a synthetic material, ground rings have to be
used to ensure that potential is equalised (see Page 39). Ground rings can be ordered
with the main product structure or as accessories → Page 85.
!
Note!
For installation in metal pipes, it is advisable to connect the ground terminal of the trans-
mitter housing to the piping. Also, observe company-internal grounding guidelines.
Fig. 37: Potential equalisation by means of the transmitter's ground terminal
"
Caution!
For sensors without reference electrodes or without metal process terminals, carry out
potential equalisation as per the instructions for special cases described below. These
special measures are particularly important when standard grounding practice cannot
be ensured or extremely strong matching currents are expected.
F06-5xxxxxxx-04-xx-xx-xx-002