Chapter 7 Earthing and Shielding
GFK-2958E
RSTi-EP User Manual
331
If you wish to avoid the disadvantages associated with creating an earth loop with two-sided shields,
it is recommended you connect one side of the shield through a high impedance.
For longer lengths of shielded cables, such as if a sensor must be added to a control panel, a
potential difference between both end points must not be ignored.
However, such shield conductors are relatively expensive and also require more time in working with
them. Another possibility would be to place an additional voltage equalizing cable between the
measurement location and the control panel. The shield can then be hooked up on both sides.
A high-impedance earth connection is also another option. In the control panel, the shield is then
connected to the earth potential, and the shield has a high-impedance connection to earth at the
measurement location via a gas discharge tube. This solves the problem of a potential transfer and
50-Hz humming.
For non-isolated measurement locations, two gas discharge tubes must be installed. One connects
the shield to earth, and the other connects it to the non-isolated measurement location. This method
prevents a galvanic coupling between the measurement circuit and the earthed measurement
location.
Содержание GFK-2958E
Страница 1: ...RSTi EP User Manual GFK 2958E November 2017 ...
Страница 23: ...Chapter 1 Introduction GFK 2958E RSTi EP User Manual 19 Notes ...
Страница 56: ...Chapter 3 Configuration GFK 2958E RSTi EP User Manual 52 Notes ...
Страница 166: ...Chapter 5 Detailed Descriptions of I O Modules GFK 2958E RSTi EP User Manual 162 EP 5111 Block Diagram EP 5111 ...
Страница 183: ...Chapter 5 Detailed Descriptions of I O Modules GFK 2958E RSTi EP User Manual 179 EP 5111 ...
Страница 184: ...Chapter 5 Detailed Descriptions of I O Modules GFK 2958E RSTi EP User Manual 180 EP 5111 ...
Страница 211: ...Chapter 5 Detailed Descriptions of I O Modules GFK 2958E RSTi EP User Manual 207 Frequency Counter EP 5212 ...
Страница 316: ...Chapter 5 Detailed Descriptions of I O Modules GFK 2958E RSTi EP User Manual 312 Notes ...
Страница 330: ...Chapter 6 Installation GFK 2958E RSTi EP User Manual 326 Notes ...
Страница 344: ...Chapter 7 Earthing and Shielding GFK 2958E RSTi EP User Manual 340 ...
Страница 345: ...Chapter 7 Earthing and Shielding GFK 2958E RSTi EP User Manual 341 Notes ...
Страница 385: ...Chapter 8 Web Server GFK 2958E RSTi EP User Manual 381 Notes ...
Страница 401: ...Chapter 11 Disassembly and Disposal GFK 2958E RSTi EP User Manual 397 Notes ...
Страница 413: ...Chapter 12 LED Indicators and Troubleshooting GFK 2958E RSTi EP User Manual 409 Notes ...
Страница 416: ...Chapter 14Accessories and Replacement Parts GFK 2958E RSTi EP User Manual 412 Notes ...