Installing and connecting the device
3.3 Connecting the device
Mobile Client900WXN
38
Operating Instructions, 04/2015, A5E35883103-AB
Connection sequence
Connect the connection box in the following sequence:
1.
Equipotential bonding
2.
Supply voltage
3.
Web server
Note
Maintaining the connection sequence
You risk damage to the connection box if you ignore the proper connection sequence.
Always adhere to the proper sequence when connecting the connection box.
3.3.1.2
Equipotential bonding of the connection box
Potential differences
Differences in potential between separated plant components can lead to high equalizing
currents over the data cables, destroying the circuits. This situation may arise if the cable
shielding is terminated at both ends and grounded at different system parts.
Differences in potential can also be caused by different mains supplies.
General requirements for equipotential bonding
Differences in potential must be reduced far enough with equipotential bonding conductors to
ensure error-free operation of the relevant electronic components. The following information
must therefore be observed when installing the equipotential bonding:
●
The effectiveness of equipotential bonding increases as the impedance of the
equipotential bonding conductor decreases or as its cross-section increases.
●
If two plant sections are interconnected by means of shielded data cables and their
shielding is connected at both ends to the grounding/protective conductor, the impedance
of the additionally installed equipotential bonding conductor must not exceed 10% of the
shielding impedance.
●
The cross-section of a selected equipotential bonding conductor must be capable of
handling the maximum equalizing current.
Experience has shown that the best equipotential bonding between two control cabinets
is achieved by following the instructions in "Description "Directives for interference-free
installation of PLCs" (
http://support.automation.siemens.com/WW/view/de/1064706
)".
●
Use equipotential bonding conductors made of copper or galvanized steel. Connect the
equipotential bonding conductors to the ground / protective conductor over a wide area.
Protect the equipotential bonding conductors against corrosion.
●
Clamp the shielding of the data cable on the HMI device flush and near the equipotential
busbar using suitable cable clamps.
Содержание SIMATIC Mobile Client900WXN
Страница 8: ...Table of contents Mobile Client900WXN 8 Operating Instructions 04 2015 A5E35883103 AB ...
Страница 28: ...Safety guidelines 2 2 Notes about usage Mobile Client900WXN 28 Operating Instructions 04 2015 A5E35883103 AB ...
Страница 88: ...Abbreviations B 1 Abbreviations Mobile Client900WXN 88 Operating Instructions 04 2015 A5E35883103 AB ...
Страница 90: ...Glossary Mobile Client900WXN 90 Operating Instructions 04 2015 A5E35883103 AB ...
Страница 94: ...Index Mobile Client900WXN 94 Operating Instructions 04 2015 A5E35883103 AB ...