Instrument grounding issue
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Regarding the grounding of the shielded end of the instrument cable, our usual practice is to ground the shielded end of the instrument cable at the cabinet, while leaving the end on the instrument side ungrounded. However, another expert suggested that not only should the shielded end be grounded at the cabinet, but it should also be grounded on the instrument side as well. I’m not sure which approach is correct; I would appreciate your guidance.
This post was last edited by ssln123 on 2022-4-26 08:19. The expertise of this expert is not impressive at all; why don’t you ask him what the consequences would be of grounding the two ends? Has he understood how shielding eliminates interference? To ground both ends, certain conditions must be met. HG/T 20513--2014 5.1 provides detailed diagrams, with 3 grounding methods for the shielding layer.
Single-sided grounding makes it relatively easier to maintain the cabinet indirectly
Are the experts referring to grounding the instrument enclosure? A new requirement that was introduced recently on our front end is that the combustible gas detectors have their enclosures grounded. It would be too simplistic to simply require grounding on both sides!
You can’t resist the demands from experts; you don’t have the confidence to confront them head-on.
Single-sided grounding, generally grounded on the instrument side
Shouldn’t the instrument shielding be single-ended grounded? Generally, the cabinet room is chosen for grounding
What if you have the “confidence”? P wants to know what the outcome will be. If you are a business owner, you would probably need to weigh the options carefully too :)
Generally, single-sided grounding is required, but in some cases, in areas where lightning strikes are frequent, it is also necessary to ground the instruments within the factory premises. This depends on the specific circumstances, and primarily on the requirements of the client. :L
Have you used a cable that combines a main screen with a split screen? If so, it is necessary to consider grounding at both ends; for more details, refer to the SHT3081-2019 Standard for Grounding Design of Petrochemical Instruments