26
FSM4000
ELECTROMAGNETIC FLOWMETER | OI/FSM4000-EN REV. E
… 5 Installation
Grounding
General information on grounding
Observe the following items when grounding the device:
• Use the supplied green/yellow cable as a grounding wire.
• Connect the ground screw for the sensor (on flange and
transmitter housing) to the station ground.
• The terminal box must also be grounded.
• 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.
• Additional grounding on the terminals is not required.
Note
If the flowmeter is installed in plastic or earthenware pipelines,
or in pipelines with an insulating lining, transient current may
flow through the grounding electrode in special cases. 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.
Metal pipe with fixed flanges
Flange design
Wafer type design
Figure 23: Grounding connections
1.
Insert M6×12 threads
2
in the flanges for the piping and the
sensor.
2.
Secure the ground straps
1
with screw, spring washer and
washer in accordance with the figure.
3.
Use a copper wire (minimum 2.5 mm² (14 AWG)) to establish
a connection between the ground connection of the sensor
and a suited grounding point.
