6
Installation
and Operation
EDBC250SIO | 2.0
186
CAUTION
External power from another network may provoke a defect of the safe I/O
module
The outputs' test pulses can detect a cross-fault or external power supplied to
the module outputs and set the module to a safe state. External power of a
higher voltage supplied to the module from another network and through the
outputs may cause current to flow into the module and destroy the it. Although
this will jeopardise the availability of the module, the module will still achieve a
safe state because the fault is detected and can be controlled safely.
Avoid the supply of external power from any source. Take particular care to
safeguard the module against an external supply of higher mains voltages by
implementing appropriate means in the application.
One such effective means could be to safely lay the output line.
CAUTION
Safe function jeopardised by cross-faults with other modules
Improper installation in conjunction with other modules may cause malfunctions
due to cross-faults at the contacts
When test pulses are enabled, the Safety I/O-module will detect cross-faults
between the inputs / outputs and other signal lines of the same module.
Note that you must prevent cross-faults with the security functions of other
modules. You should therefore protect the signal lines and/or lay them sep-
arately.
Figure 9: Avoid a supply of external power, particularly of higher mains voltages
