Regarding the ground resistance and ground connection resistance of instrumentation and control systems
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In SHT 3081-2019 \"Code for Design of Grounding of Instrumentation in Petrochemical Industries\", what do the grounding resistance of instrumentation and control systems, as well as the grounding connection resistance, refer to? And how are they measured? Is there any relationship between the value of ground resistance and the value of ground connection resistance? Please ask
The ground resistance is the resistance measured at a distance specified by the standards. The connection resistance should be the value of resistance from the instrument’s grounding point to the nearest equipotential connection point; I’m not entirely sure if that’s correct:P
The ground resistance consists of two parts: the resistance of the grounding electrode to the ground, and the resistance between the grounding point and the grounding electrode. The former is the ground resistance, while the latter is the ground connection resistance. The ground resistance is measured using a ground resistance meter, which has three measurement probes. The distance between the ground measurement probe and the ground resistance meter, as well as the distance between the various ground probes, must meet the specified requirements for accurate measurement. A high ground resistance and ground connection resistance result in weak current-carrying capacity; the potential at the grounding point rises, the reference potential increases, and the interference resistance decreases. A low ground resistance increases the cost of grounding projects.
Look, sections 3.19 and 3.20 of this standard provide explanations; a ground resistance tester is used to measure ground resistance