Control Panel User Manual
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distribution). Metal hoses are applicable to ceiling wiring, but must be
secure and good-looking.
Shielding measures and shielding connection: If the electromagnetic
interference in the wring environment is found strong in the survey before
construction, it is necessary to consider shielding protection for data
cables when designing a construction scheme. Overall shielding
protection is required if there is a large radioactive interference source or
wiring has to be parallel with a large-current power supply on the
construction site. Generally, shielding measures include: keeping a
maximum distance from any interference source, and using metal wiring
troughs or galvanized metal water pipes to ensure reliable grounding of
the connection between the shielding layers of data cables and the metal
troughs or pipes. Note that a shielding enclosure can have a shielding
effect only when it is grounded reliably.
Ground wire connection method: Reliable large-diameter ground wires in
compliance with applicable national standards are needed on the wiring
site, and should be connected in a tree form to avoid DC loop. These
ground wires must be kept far away from lightning fields. No lightning
conductor can serve as a ground wire, and ensure there is no lightning
current through any ground wire when there is lightning. Metal wiring
troughs and pipes must be connected continuously and reliably, and
linked to ground wires through large-diameter wires. The impedance of
this section of wire cannot exceed 2ohm. The shielding layer also must be
connected reliably, and grounded at one end to guarantee uniform current
direction. The ground wire of the shielding layer must be connected
through a large-diameter (not smaller than 2.5mm
2
) wire.
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