●
For connecting cables exposed to UV radiation (outdoor installation), use UV
resistant cables.
●
For the connection of position transmitters, screened cables must be used.
Cable installation in ac-
cordance with EMC
Signal and fieldbus cables are susceptible to interference. Motor cables are
interference sources.
●
Lay cables being susceptible to interference or sources of interference at the
highest possible distance from each other.
●
The interference immunity of signal and fieldbus cables increases if the cables
are laid close to the earth potential.
●
If possible, avoid laying long cables and make sure that they are installed in
areas being subject to low interference.
●
Avoid parallel paths with little cable distance of cables being either susceptible
to interference or interference sources.
HART cable recommend-
ation:
Twisted wire pair, shielded.
For cable length <1,500 m: Cross section min. 0.2 mm²
For cable length >1,500 m: Cross section min. 0.5 mm²
We recommend selecting 0.75 mm² cross section. For smaller cable length cross
section, the cross section must be enlarged to min. 0.75 mm² using a wire end sleeve
if required and performing an appropriate concentric crimping.
Multiple-twisted pair cables must not be used.
Prior to installation, please note:
●
Connection is made as point-to-point topology.
●
Respect a distance of minimum 20 cm between HART cables and other cables
if possible. The cables should be laid in a separate, conductive, and earthed
cable tray, if possible.
●
Make sure that there are no potential differences between participants.
●
Maximum cable length depends on characteristics of devices connected (im-
pedance), of cables used (cable capacity and resistance) and the impedance
of all devices installed between two end devices.
6.2.
Overview of AUMA electrical connections
The section below provides an overview of the different electrical connections
described in the chapters to follow.
28
SAEx 07.2 – SAEx 16.2/SAREx 07.2 – SAREx 16.2 Control unit: electronic (MWG)
Electrical connection
ACExC 01.2 Non-Intrusive HART
