7 Mounting
24
7.3.1
Make sure that the potential is equal in the installation
Measures for making sure the potential is equal in the installation (voltage supply
device
measure-
ment medium):
•
Connect the various grounding points in the installation to make sure any difference in potential be-
tween two grounding points is eliminated.
•
Make sure both ends of the supply cable's shielding are grounded correctly.
•
Connect the negative terminal on the voltage supply to the ground to suppress the effects of common
mode currents. If you cannot connect the two elements directly, you can switch a capacitor with
100 nF/50 V between the voltage supply's negative terminal and the ground.
•
If the device is installed on plastic pipes, please pay particular attention to the following: direct
grounding is not possible in this case. For correct grounding, connect all metallic objects close to the
device (valves or pumps) to the same grounding point. If there are no metallic objects near the de-
vice, insert grounding rings into the device in both the flow direction and against the flow direction;
connect these rings with the same ground. The grounding rings must be in contact with the measure-
ment medium.
Wiring diagrams for potential equalization in plastic pipelines
(1)
Voltage supply
(2)
If direct grounding is not possible, connect a capacitor with 100 nF/50 V between the voltage sup-
ply's negative terminal and the ground.
(3)
Pumps, motors, valves
Alternative: Grounding rings inserted in the pipeline (not included in the scope of delivery)
(4)
Plastic pipeline
(5)
Shielding on the supply cable
