Endress+Hauser HART Flowmeter Proline 400 Brief Operating Instructions page 33

Flowmeter Proline 400
3.
2.
PE
 12 Promag L, W
1. Connect the pipe flanges and transmitter via the ground cable.
2. Route the shielding of the signal lines via a capacitor (recommended value 1.5µF/50V).
3. Device connected to power supply such that it is floating in relation to the protective
earth (isolation transformer). This measure is not required in the case of 24V DC supply
voltage without PE (= SELV power unit).
5.4.4 Promag W: Connection examples with the potential of the medium not equal to
the protective ground with the "Measurement isolated from ground" option
In these cases, the medium potential can differ from the potential of the device.
Introduction
The "Measurement isolated from ground" option enables the galvanic isolation of the
measuring system from the device potential. This minimizes harmful equalizing currents
caused by differences in potential between the medium and the device. The "Measurement
isolated from ground" option is optionally available: order code for "Sensor option", option CV
Operating conditions for the use of the "Measurement isolated from ground" option
Device version
Differences in voltage between medium potential and device
potential
Alternating voltage frequencies in the medium or at ground
potential (PE)
• To achieve the specified conductivity measuring accuracy, a conductivity calibration is
recommended when the device is installed.
• A full pipe adjustment is recommended when the device is installed.
Endress+Hauser
+
–
≠ P = P
P M
A0042253
3.
2.
 13 Promag D
Compact version and remote version
(Length of connecting cable ≤ 10 m)
As small as possible, usually in the mV range
Below typical power line frequency in the country
Electrical connection
+
–
PE ≠ P = P
P M
A0045826
33