Potential Compensation; Switching Inductive Loads - turck IO-LINK MASTER User Manual

Electromagnetic compatibility (EMC)

Potential compensation

Potential differences can occur between installation components that are in separate areas
and these
are fed by different supplies,
have double-sided conductor shields which are grounded on different installation compo-
nents.
A potential-compensation cable must be routed to the potential compensation.
Connection A
B
A
Figure 40:
Potential
compensation
Reference potential
A potential compensation cable must have the following characteristics:
Low impedance. In the case of compensation cables that are routed on both sides, the
compensation line impedance must be considerably smaller than that of the shield
connection (max. 10 % of shield connection impedance).
Should the length of the compensation cable be less than 200 m, then its cross-section
must be at least 16 mm
cross-section of at least 25 mm
The compensation cable must be made of copper or zinc coated steel.
The compensation cable must be connected to the protective conductor over a large
surface area and must be protected against corrosion.
Compensation cables and data cables should be routed as close together as possible,
meaning the enclosed area should be kept as small as possible

Switching inductive loads

In the case of inductive loads, a protective circuit on the load is recommended.
D301171 - IO-Link master 1108
Warning
Never use the shield as a potential compensation.
3 0 ------------- 0 3
5 0
8 0 ------------- 0 8
Potential compensation cable
2
/ 0.025 inch
Connection B
0 5
Shield
2
. If the cable length is greater than 200 m, then a
2 2
/ 0.039 inch is required.
B
A
Reference potential
6
6-7