JUMO 406060, Operating Manual

Page: 23 / 116

5 Installation
23
5.4 Sensor grounding
5.4.1 General information on grounding
Observe the following items when grounding the device:
• For plastic piping or piping with insulating liner, the ground
is provided by the grounding plate or grounding
electrodes.
• When stray potentials are present, install a grounding
plate upstream and downstream of the sensor.
• For measurement-related reasons, the potential in the
station ground and in the piping should be identical.
Note
If the sensor is installed in plastic or earthenware pipelines, or in
pipelines with an insulating liner, compensating currents may flow
through the grounding electrode in special cases (e.g. with
corrosive measuring media, acids and bases)
In the long term, this may destroy the sensor, since the ground
electrode will in turn degrade electrochemically.
In these special cases, the connection to the ground must be
performed using grounding plates. Install a grounding plate
upstream and downstream of the device in this case.
5.4.2 Metal pipe with fixed flanges
A
Flange design
B
Wafer type design
1
Ground terminal
Figure 25: Metal pipe, without liner (example)
Use a copper wire [at least 2.5 mm
2
(14 AWG)] to establish the
connection between the ground terminal of the sensor, the
pipeline flanges and a suited grounding point in accordance with
the figure.
5.4.3 Metal pipe with loose flanges
A
Flange design
B
Wafer type design
1
Threaded bolts M6
2
Ground terminal
Figure 26: Metal pipe, without liner (example)
1.

Solder the threaded bolts M6 to the piping and connect the
ground in accordance with the figure.
2.

Use a copper wire [at least 2.5 mm
2
(14 AWG)] to establish
the connection between the ground terminal of the sensor and
a suited grounding point in accordance with the figure.