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Electrical installation
3ADW000379R0501 DCS550 Manual e e
Control / signal cables
Used screened cables for digital signals, which are longer than 3 m and for all analog signals. Connect each
screen at both ends by metal clamps or comparable means directly on clean metal surfaces, if both earthing
points belong to the same earth line. Otherwise, connect a capacitor to earth on one end. In the converter
cabinet this kind of connection must be made directly on the sheet metal close to the terminals and if the cable
comes from outside also on the PE bar. At the other end of the cable, connect the screen well with the
housing of the signal emitter or receiver.
Connection of cable screens with
metal clamps to the metal
surface of the electronic tray.
A double shielded twisted pair cable, e.g. JAMAK by NK Cables, Finland, must be used for analog signals and
the pulse encoder signals. Employ one individually shielded pair for each signal. Do not use common return
for different analog signals.
A double shielded cable is the best alternative for low voltage digital signals but single shielded twisted multi
pair cable is also usable.
Double shielded twisted pair cable
Single shielded twisted multi pair cable
− Pairs should be twisted as close to terminals as possible.
− Run analog and digital signals in separate, screened cables.
− Relay-controlled signals, providing their voltage does not exceed 48 V, can be run in the same cables as
digital input signals. It is recommended that the relay-controlled signals be run as twisted pairs too.
Attention:
Never run 24 V
DC
and 115 / 230 V
AC
signals in the same cable!
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