Vega VEGAPULS 67 Operating Instructions Manual page 26

5 Connecting to power supply
Cable screening and
grounding
Cable screening and
grounding
Cable screening and
grounding
26
NPT thread
In the case of instrument housings with self-sealing NPT threads, it is
not possible to have the cable entries screwed in at the factory. The
free openings for the cable glands are therefore covered with red dust
protection caps as transport protection.
Prior to setup you have to replace these protective caps with ap-
proved cable glands or close the openings with suitable blind plugs.
With plastic housing, the NPT cable gland or the Conduit steel tube
must be screwed without grease into the threaded insert.
Max. torque for all housings, see chapter "Technical data".
If screened cable is required, we recommend connecting the cable
screen on both ends to ground potential. In the sensor, the screen
must be connected directly to the internal ground terminal. The
ground terminal on the outside of the housing must be connected to
the ground potential (low impedance).
In Ex systems, the grounding is carried out according to the installa-
tion regulations.
In electroplating and CCP systems (cathodic corrosion protection) it
must be taken into account that significant potential differences exist.
This can lead to unacceptably high currents in the cable screen if it is
grounded at both ends.
Information:
The metallic parts of the instrument (process fitting, sensor, concen-
tric tube, etc.) are connected with the internal and external ground
terminal on the housing. This connection exists either directly via
the conductive metallic parts or, in case of instruments with external
electronics, via the screen of the special connection cable.
You can find specifications on the potential connections inside the
instrument in chapter "Technical data".
If screened cable is required, we recommend connecting the cable
screen on both ends to ground potential. In the sensor, the screen
must be connected directly to the internal ground terminal. The
ground terminal on the outside of the housing must be connected to
the ground potential (low impedance).
In Ex systems, the grounding is carried out according to the installa-
tion regulations.
If screened cable is required, we recommend connecting the cable
screen on both ends to ground potential. In the sensor, the screen
must be connected directly to the internal ground terminal. The
ground terminal on the outside of the housing must be connected to
the ground potential (low impedance).
In Ex systems, the grounding is carried out according to the installa-
tion regulations.
VEGAPULS 67 • 4 ... 20 mA/HART - four-wire