6
Installation
and Operation
EDBC250SIO | 2.0
167
HF interference is dissipated from the electronics board to the metal housing. The metal hous-
ing therefore needs to be suitably connected to a functional earth connector. You would nor-
mally ensure that the connection between the module housing and the DIN rail as well as the
connection between the DIN rail and the control cabinet conducts well and that the control
cabinet is properly connected to earth.
In exceptional cases, you may connect earth directly to the front of the module.
Figure 5: Aluminium profile in the Safety I/O-module
Note, information
Earth wires should be short and have a large surface (copper mesh). Refer to
http://de.wikipedia.org/wiki/ground_(electronics) for further details
Note, information
When installing production or other lines, measure the earth potential of the
DIN rail as specified in the applicable guidelines (earth test to VDE 0100). Meas-
uring the earth potntial must show that every protective earthing and opera-
tional earthing is within the boundaries set by the applicable standards. Also
consider the repeat testing frequency resulting from the hazard assessment.
6.3.2
Ground connection
When connecting the ground potential (GND or "L-") of the module and the connected actua-
tors, the following instructions must be observed:
•
Use a separate GND line for each actuator to a common GND potential rail and no GND sum
lines which can cause a critical error for two or more actuators due to a single error.
•
Non-safety-relevant output modules and their actuators must be routed to the GND poten-
tial rail via their own GND line and must not share a GND line with safety-relevant func-
tions!
•
Ensure a safe connection of the module GND potential ("L-", pin 17 and pin 35 of the front
connector of the modules) with the GND potential rail.
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