32
FEM630 | ELECTROMAGNETIC FLOWMETER  |  OI/FEM630-EN REV. A
6     ...Electrical connections
...Sensor grounding
Mixed system, piping with cathodic corrosion potential 
and functional ground potential
Power supply
Note
•  Adhere to the limit values of the power supply in 
accordance with the information on the name plate.
•  Observe the voltage drop for large cable lengths and 
small conductor cross-sections. The voltage at the 
terminals of the device may not down-scale the minimum 
value required in accordance with the information on the 
name plate.
The power supply is connected to terminal L (phase), N (zero), 
A circuit breaker with a maximum rated current of 16 A must 
be installed in the power supply line.
The wire cross-sectional area of the power supply cable and 
the circuit breaker used must comply with VDE 0100 and must 
be dimensioned in accordance with the current consumption 
of the flowmeter measuring system. The cables must comply 
with IEC 227 and/or IEC 245.
The circuit breaker must be located near the device and 
marked as being associated with the device.
Connect the transmitter and sensor to functional earth.
This mixed system has an insulated piping with corrosion 
protection potential and an uninsulated metal pipe (L = ¼ × 
DN sensor) with functional ground potential upstream and 
downstream of the sensor.
Figure 33 shows the preferred installation for cathodic 
corrosion protection.
G11048
121
A
2
3
B
B
B
B
Connection line corrosion potential*
Insulated screw bolts without grounding plates
Insulated piping  
Uninsulated metal piping  
Functional ground
 Cu, not included in the delivery, to be provided on-site
A
B
1
2
3
Figure 33  Sensor with functional ground