Distance between instrument grounding electrode and electrical grounding electrode
Thread Content
The design institute requires that the distance between the instrument grounding electrode and the electrical grounding electrode be at least 30 meters. But if both the instrument grounding and the electrical grounding are done using the same grounding electrode, how is that possible? For specific discussions, see http://bbs.hcbbs.com/thread-569196-1-1.html; it’s confusing to me – who is at fault exactly?
Personally, I think they shouldn’t be combined; I’m not sure what others think
The farther, the better. In fact, all the equipment and pipelines in a factory building are connected to the ground where the building is located; the electrical grounding is also in the foundation of the building. So where should the instruments be installed? The ground itself acts as a large capacitor; the potential at various points within the ground is theoretically equal. However, when an interference voltage from an electrical system is released into the ground, if there is a grounding wire for instruments in the vicinity, this voltage will definitely be transmitted to that instrument’s grounding wire (this has been confirmed!) ! ! ! So theory is theory, but reality is reality!
There is only one ground grid; unless two separate ground grids are established during the civil construction work, the distance between the grounding points for instruments and electrical equipment also depends on the voltage level