Connection With Four-Wire Configuration; Emc Protection - HBM U10M Montageanleitung

U10M, U10S
The cable shield is connected with the transducer housing. Only use plugs
that meet EMC guidelines. The shielding must be connected extensively. With
other connection techniques, an EMC-proof shield should be applied in the
wire area and this shield should also be connected extensively (see also HBM
Greenline Information, brochure i1577).

6.2 Connection with four-wire configuration

When transducers with a six-wire configuration are connected to amplifiers
with a four-wire configuration, the sense leads of the transducer must be con-
nected to the corresponding supply leads: Identification (+) with (+) and identi-
fication (−) with (−), see Fig 6.1. This measure also reduces the cable resist-
ance of the excitation voltage leads. However, there will be a voltage loss on
the supply leads due to the cable resistance that is still present and not com-
pensated for by the six-wire configuration. A large part of this loss can be
eliminated by a calibration, however, the temperature-dependent part remains.
The TK value given in the specifications for the transducer therefore does not
c
apply for the cable and transducer combination when connection is with four-
wire configuration, the cable percentage must be added.

6.3 EMC protection

Electrical and magnetic fields often induce interference voltages in the mea-
suring circuit. Therefore:
• Use shielded, low-capacitance measurement cables only (HBM cables
fulfill both conditions).
• Do not route the measurement cables parallel to power lines and control
circuits. If this is not possible, protect the measurement cable with e. g. steel
conduit.
• Avoid stray fields from transformers, motors and contact switches.
• Do not ground the transducer, amplifier and indicator more than once.
• Connect all devices in the measurement chain to the same grounded
conductor.
• Always connect the cable shield extensively to the connector housing.
A1385−6.0 en/de/fr
23
HBM