Endress+Hauser HART Flowmeter Proline 400 Brief Operating Instructions page 34

Electrical connection
Plastic pipe
Sensor and transmitter are correctly grounded. A difference in potential can occur between
the medium and protective earth. Potential equalization between P
electrode is minimized with the "Measurement isolated from ground" option.
Starting conditions:
• The pipe has an insulating effect.
• Equalizing currents through the medium cannot be ruled out.
PE = P ≠ P
 14 Promag W
1. Use the "Measurement isolated from ground" option, while observing the operating
conditions for measurement isolated from ground.
2. Connect the connection housing of the transmitter or sensor to ground potential by
means of the ground terminal provided for this purpose.
Metal, ungrounded pipe with insulating liner
The sensor and transmitter are installed in a way that provides electrical insulation from PE.
The medium and pipe have different potentials. The "Measurement isolated from ground"
option minimizes harmful equalizing currents between P
Starting conditions:
• Metal pipe with insulating liner
• Equalizing currents through the medium cannot be ruled out.
34
P M
A0044855
and PE via the reference
M
and P via the reference electrode.
M P
Flowmeter Proline 400
Endress+Hauser