Proface LT4300M - 5.7 Modular HMI + Control" - Manual (Page 38)

38
English
The diagram illustrates a lightning surge absorber connection:
Grounding the System
To minimize the effects of electromagnetic interference, cables carrying the fast I/O,
analog I/O, and Serial communication signals must be shielded.
1 To avoid damage to the shielded cable when there is a short circuit in the power line, set
up a multi-point frame ground (FG) each with the same electric potential.
The use of shielded cables requires compliance with the following wiring rules:
 When there is no protective earth ground, you can use metal conduit or cable duct
shield as a part of the protective earth ground. The functional ground (FE) shield must
attenuate electromagnetic interference and must be shielded the length of the cable. If
the purpose is for both functional and protective grounding, as is often the case for
communication cables, the cable must have continuous shielding.
 Wherever possible, keep cables carrying one type of signal separate from the cables
carrying other types of signals or power.
Protective Earth Ground on the Backplane
For protective grounding, connect braided copper cable (that can withstand the maximum
voltage/current allowed by the system) to the conductive backplane.
WARNING
IMPROPER GROUNDING CAN CAUSE UNINTENDED EQUIPMENT OPERATION
 Use cables with insulated shielded jackets for analog I/O, fast I/O and communication
signals.
 Ground shielded cables for analog I/O, fast I/O and communication signals at a single
point
1 .
 Always comply with local wiring requirements regarding grounding of cable shields.
Failure to follow these instructions can result in death, serious injury, or
equipment damage.