Regarding ground resistance
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Now, DCS systems all have a requirement for system ground resistance, which seems to be no more than 4 ohms. Now I want to know how the ground resistance of this system actually works, and what happens if it exceeds 4 ohms? I see that in the Yokogawa CS3000 system it is specified that its system ground resistance can be 100 ohms. Does this indicate that his anti-interference performance is better? I hope everyone can provide an answer. This post was last edited by naska on 2008-2-28 09:03.]
Ground resistance is one of the parameters that ensure the safety of people and equipment. In the event of a ground fault, a high ground resistance leads to an increased deviation in the voltage at the neutral point, which can cause the voltages at the healthy phases and at the neutral point to become too high, exceeding the levels required for insulation. When lightning strikes or lightning waves arrive, the high current generates a very high residual voltage, posing a risk of backflow damage to nearby equipment. The grounding of DCS refers to combined grounding; most DCS manufacturers use a resistance value of 4 ohms, while Yokogawa indeed uses 100 ohms. This difference is due to variations in the systems. As for why Yokogawa can achieve a resistance value of 100 ohms, their technology is certainly not something they would reveal to others. However, the more lenient the system’s requirements regarding the ground resistance at the site, the better it is for the buyer – there is no need for driving piles or using resistance reduction devices, which helps to reduce costs. I know of exaggerated customers who, using Yokogawa’s systems, directly connect the ground wire to the radiators.
I’ve learned it, hehe:victory: