Extension Cables And Cable Shortening; Emc Protection - HBM U2B serie Montageanleitung

7.2

Extension cables and cable shortening

Various connection cable lengths are available for the U2B so that extension
cables or cable shortening are generally not necessary.
The transducer is executed in a 6-wire configuration, to compensate for cable
influences; this also applies to the temperature coefficient of sensitivity.
The maximum possible cable length depends on the ohmic resistance of the
cable, its capacity and the amplifier being used. Use suitable shielded, low-
capacitance cables for the strain gage sensors, to ensure perfect measure­
ment results.
With extension cables, ensure that the connection is perfect with a low contact
resistance and continue to connect the cable shield extensively. Note that the
protection class of your force transducer will decrease if the cable connection
is not tight and water can penetrate the cable. Transducers can be irreparably
damaged and fail in these circumstances.
7.3

EMC protection

Electrical and magnetic fields can often induce interference voltages in the
measuring circuit. Pay attention to the following points to avoid this:
S Use shielded, low-capacitance measurement cables only (HBM cables fulfill
both conditions)
S Do not route the measurement cable parallel to power lines and control cir­
cuits. If this is not possible, protect the measurement cable with metal tub­
ing.
S Avoid stray fields from transformers, motors and contact switches.
S Do not ground transducers, amplifiers and indicators more than once.
S Connect all the devices in the measuring chain to the same protective con­
ductor.
S Always connect the cable shield extensively on the amplifier side and on the
transducer side, to create the best possible Faraday cage.
U2B
A00382_03_YI0_06 HBM: public
Electrical connection
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