Electrical Connection; Notes On Cabling - HBM U2B Notice De Montage

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5

Electrical connection

5.1 Notes on cabling

Electrical and magnetic fields often cause noise voltage induction in the mea
suring circuit. This interference arises most commonly from high power trans
mission lines running parallel to the measuring circuits, but may also come
from nearby protective contacts or electric motors. Noise voltage induction
can also occur on galvanic paths, especially if the measuring equipment is
earthed at several points.
Please note the following instructions:
• Use only shielded, low capacitance measuring cable from HBM.
• Lay measuring cable so that it is not parallel to high tension lines or control
circuits. If this is not possible (e.g. in cable shafts), protect the measuring
cable with e.g. steel conduit and keep it at least 50 cm away from the other
cables. High tension lines or control circuits should be twisted (15 turns per
metre).
• Stray fields from transformers, motors and protective contacts must be
avoided.
• Do not multi earth transducers, amplifiers and display devices. All devices
in the measuring system must be connected to the same protection circuit.
• Link the connector cable shield to the transducer housing.
• Connection diagram, earthing scheme (Green Line)
HBM
U2B
A0382 3.3 en/de/fr