GE GFK-2958E, User Manual

Page: 343 / 425

Chapter 7 Earthing and Shielding
GFK-2958E RSTi-EP User Manual 339
7.4.1 Equipotential Bonding
If system components are positioned separately from each other, potential differences may arise,
provided that:
•
Power is provided from different sources
•
The earthing is implemented at different system parts, despite the cable shields being
connected at both sides
A voltage equalizing cable must be used for equipotential bonding.
Warning
The shield must not be used for equipotential bonding.
The following features are essential for a voltage equalizing cable:
•
In the case of cable shields on both ends, the impedance of the equalising cable must be
considerably smaller than that of the shield connection (maximum 10 % of its impedance)
•
When the length of the equalising cable is less than 200 m (656.2 ft), its cross-section must be
at least 16 mm
2
(0.025 in
2
).If the cable is greater than 200 m (656.2 ft) in length, a cross-
section of at least 25 mm
2
(0.039 in
2
)is necessary.
•
Large-surface connection with the PE conductor or the earthing and corrosion protection are
requirements for long-term safe operation
•
They must be made of copper or galvanised steel
•
In order to keep the enclosed area as small as possible, the equalising cable and signal cable
must be routed as close to each other as possible
7.4.2 Inductance wiring
For inductive loads, it is recommended that protective circuits be placed directly on the load. The
earth (PE/FE) must be connected in a neutral-point configuration according to regulations for switch
cabinets.
Caution
When disassembled, RSTi-EP modules and network adapters are at risk of
electrostatic discharge (ESD). Therefore, avoid touching bus connections with
bare hands, as this can lead to damage due to electrostatic discharges.