Electrical Connection; General Information; Emc Protection - HBM T40B Mounting Instructions

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5

Electrical connection

5.1 General information

 With cable extensions, make sure that there is a proper connection with
minimum contact resistance and good insulation.
 All cable connectors or swivel nuts must be fully tightened.
Important
Transducer connection cables from HBM with plugs attached are identified in
accordance with their intended purpose (Md or n). When cables are
shortened, inserted into cable ducts or installed in control cabinets, this identi­
fication can get lost or become concealed. Mark the cables before laying them
in this case.

5.2 EMC protection

Important
The transducers are EMC‐tested in accordance with EC directives and identi­
fied by CE certification. However, you must connect the shield of the connec­
tion cable on the shielding electronics enclosure in order to achieve EMC pro­
tection for the measuring chain.
Special electronic coding methods are used to protect the purely digital signal
transmission between the transmitter head and the rotor from electromagnetic
interference.
The cable shield is connected with the transducer housing. This encloses the
measurement system (without the rotor) in a Faraday cage when the shield is
laid flat at both ends of the cable. With other connection techniques, an
EMC­proof shield should be applied in the wire area and this shielding should
also be connected extensively (also see HBM Greenline Information, brochure
i1577).
Electrical and magnetic fields often induce interference voltages in the meas­
uring circuit. Therefore:
 Use shielded, low‐capacitance measurement cables only (HBM cables ful­
fill both conditions).
 Only use plugs that meet EMC guidelines.
HBM
T40B
A3452-4.0 en/de