Chapter 5: Special Installations; Em Contaminated Environments; Cabling - Fluke VIBRONET Signalmaster Installationsanleitung

Chapter 5: Special installations

5.1 EM contaminated environments

Sources of severe electromagnetic interference in the vicinity of
cables require special installation procedures in order to ensure that
the VIBRONET CMS functions properly. This type of interference can
occur, for example, due to:
- Frequency converters
- Radio or remote control transmitters
- High-voltage cables

Cabling

Use a double-shielded triaxial cable (e.g. VIB 90080) for connecting
sensors to MUXes in electromagnetically contaminated environments.
To facilitate the installation you may use coaxial cable for the first
several meters. The transition to triaxial cable is made with the help
of the junction box VIB 6.770/13. PLC connections are made without
the junction box.
Connecting triaxial cable to junction box VIB 6.770/13:
• Open the housing of the junction box.
• Remove the threaded fitting and insert the end of the triaxial cable
through it.
• Wrap the exposed shield around the fitting.
• Strip the insulation from the signal conductor and its shield.
• Connect the signal conductor to the white lead and the shield to
the blue lead.
• Reassemble the junction box, then the fitting.
Risk of broken cable
Turn the metal tube and hold the fittings firmly so that the cable con-
nection does not tear off.
• Mount the junction box electrically isolated in order to avoid
ground loops.
Signal (white)
TNC
to sensor
Shield (blue)
(coaxial)
Note
Wrap shield around fitting
Junction box VIB 6.770/13 with
threaded fitting M20 for triaxial
Fitting M 20
cables
to MUX
(triaxial)
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Special installations