Grounding the system, Warning – Proface LT4300M - 5.7 Modular HMI + Control" User Manual
Page 38
LT System General Implementation Rules
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Grounding the System
Overview
To minimize the effects of electromagnetic interference, cables carrying the fast I/O, analog I/O,
and Serial communication signals must be shielded.
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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.
Functional Ground on the DIN Rail
The DIN rail for your LT is common with the functional ground plane and must be mounted on a
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.
WARNING
UNINTENDED EQUIPMENT OPERATION
When connecting DIN rails, connect the DIN rails to functional ground (FE).
Failure to follow these instructions can result in death, serious injury, or equipment
damage.