B.1 Field Grounding and Shielding Applications
Unfortunately, it’s impossible to finish a system integration task at one time. We always meet some trouble in the field. A communication network or system isn’t sta- ble, induced noise or equipment is damaged or there are storms. However, the most usual issue is just simply improper wiring, ie, grounding and shielding. You know the 80/20 rule in our life: we spend 20% time for 80% work, but 80% time for the last 20% of the work. So is it with system integration: we pay 20% for Wire / Cable and 0% for Equipment. However, 80% of reliability depends on Grounding and Shielding. In other words, we need to invest more in that 20% and work on these two issues to make a highly reliable system. This application note brings you some concepts about field grounding and shielding. These topics will be illustrated in the following pages.
B.2 Grounding
B.2.1 The ‘Earth’ for reference
Figure B.1 Think the EARTH as GROUND
As you know, the EARTH cannot be conductive. However, all build- ings lie on, or in, the EARTH. Steel, concrete and associated cables (such as lighting arresters) and power system were connected to EARTH. Think of them as resistors. All of those infi- nite parallel resistors make the EARTH as a single reference point.
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