Sensor Earth Connection - Tecfluid FLOMID Series Instruction Manual

5.3

Sensor earth connection

To obtain correct operation the sensor should have its functional earth connected to a point
that is in direct contact with the liquid whose flow rate wants to be measured.
The earth cables should assure a good electrical contact. To obtain this, they should be well
screwed down and with a good contact on both sides of the sensor. It is important to
eliminate paint or coverings that act as insulation of the connection.
The functional earth connection should be used exclusively for the sensor given that parasitic
signals caused by other electrical equipment connected to this earth can cause malfunction
of the sensor.
In the case that there are high voltage differences between different earth points, this will
cause currents that may give problems in the readings (empty pipe indication). In these
cases, do not connect the functional earth to the protective earth of the mains.
The connection of the functional earth should be made as follows:
a) In the case of metallic pipes without internal lining connect the earth cables to the
counter flanges.
b) In the case of metallic pipes with internal lining or plastic pipes, connect the earth
cables to the earthing disks, supplied on request.
The earthing disks are necessary when the installation is with plastic pipes or metallic pipes
with an internal insulating lining (PTFE, PVDF, PP, EBONITE etc.).
13