Technical Information
Chapter
4
TiM51x
Electrical installation
8016425/YZK8/2016-07-07
©
SICK AG · Germany · All rights reserved · Subject to change without notice
14
Remedial measures
The primary solution for avoiding equipotential bonding currents on the cable shields is to
guarantee low-impedance and current-conducting potential equalization. If this is not pos-
sible, the following two solution approaches are intended as suggestions.
Important
It is not advisable to open up the cable shields. This can cause compliance with EMC limit
values for the devices to be no longer guaranteed.
a) Measures for widely distributed system installations
On widely distributed system installations with correspondingly large potential differences,
we recommend setting up local islands and connecting them using commercially available
electro-optical signal isolators
. This will attain maximum resistance to electromagnetic in-
terference, while observing all requirements of EN 60950-1 at the same time.
The ground loop is isolated by using the electro-optical signal isolator between the islands.
Equalization currents are prevented on the cable shields within the islands by conductible
equipotential bonding.
b) Measures for small system installations
For smaller installations with only slight potential differences, insulated installation of the
TiM51x and of peripheral devices may be a sufficient solution.
Actuators for
switching outputs
grounding point 1
Electro-
optical
signal
isolators
Electro-
optical
signal
isolators
grounding point 2
= metal housing
= shielded electrical cable
= fiber optic cable
grounding potential difference
U
TiM51x
Actuators for
switching outputs
grounding point 2
grounding point 3
grounding point 1
Power
supply unit
= metal housing
= shielded electrical cable
electrically
insulated
U
grounding potential difference
TiM51x
