2 Function description
BU 0630 en-2020 27
Monitored outputs
SK 510P, SK 540P SK30P, SK 550P with SK CU5-STO or SK CU5-MLT
protective switching
device
cables
protective switching
device
Block
Block
In this case, a shielded cable is not necessarily essential if the safety outputs are monitored. If, for
example, other 24 V control cables are installed in the same cable duct and a fault in the form of a
short-circuit of the output of the protective switching device (24 V) to a control cable (= 24 V) is
assumed, this fault would be detected by the output monitoring of the switching device and the Safe
Pulse Block would be triggered by the second safety output. Dangerous situations may occur with a
short-circuit of a control cable (= 24 V) to both safety outputs (24 V). More precise details result from
the risk assessment and the FMEA for the specific application.
If no shielded cable is used for wiring the safety function, possible effects of electromagnetic fields
must be taken into account. Hence, the use of a 1 m long cable (in a separate cable duct) in an
environment without strong electromagnetic fields is relatively safe, whereas the installation of a long
cable in the direct vicinity of a powerful transmitter or a medium voltage distributor may cause failure
of the safety function. Because of this, use of shielded cables is generally recommended.
Pos: 122 /A nleit ung en/El ek tr onik /Saf ety /4. M on tage un d I nstal la tio n/M ontag e u nd I nst alla tio n (Ü bers chr ift +) @ 1 5\mod_1485428773104_388.docx @ 2316139 @ 1 @ 1
To Next Page
Loading...
