Installing and connecting the display unit
3.3 Connecting the display unit
IRD400
Operating Instructions, 05/2018, A5E36790512-AC
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General requirements of equipotential bonding
You must reduce potential differences to the possible minimum by installing equipotential
conductors to ensure proper functioning of the respective electronic components. For this
reason, observe the following rules when installing the equipotential bonding circuit:
●
The effectiveness of equipotential bonding increases proportionally with lower impedance
or greater cross-section of the equipotential bonding conductor.
●
If two plant components are interconnected by means of shielded data cables and their
shielding is grounded at both ends, the impedance of the additionally installed
equipotential bonding conductor may not exceed 10 % of the shielding impedance.
●
The cross-section of an equipotential bonding conductor must be of sufficient size to cope
with the maximum equipotential current.
In practical life, equipotential bonding conductors with a minimum cross-section of
16 mm² are generally accepted for the interconnection between control cabinets or with
grounding busbars.
●
Use equipotential bonding conductors made of copper or galvanized steel.
Interconnect the equipotential bonding conductors and the earth rod/protective conductor
on a large surface and protect these against corrosion.
●
Use a suitable cable clamp to bond the shielding of the data cable flush to the
equipotential busbar. Keep the length of cable between the device and the equipotential
bonding rail as short as possible.
●
Route the equipotential bonding conductors and data cables in parallel and with minimum
clearance between them.
Wiring diagram
The following figure shows a practical example of a display unit that is installed in a control
cabinet. The display unit is wired accordingly in the carrier controller.
NOTICE
Risk of damage to interface modules
You risk damage or destruction of the interface modules if using cables with inappropriate
minimum cross-section for functional ground.
Always use conductor cross-sections as shown in the following figure for functional ground.
