Process Engineering Division – Instrumentation and Automation Section – Daily Question – Question from 2020-07-16
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Process Engineering Division – Instrumentation and Automation Section – Daily Question – Question from 2020-07-16: Discussion question: 178. What does working grounding include?
To ensure the reliable operation of electrical equipment under normal or fault conditions, grounding a certain point in the power system is referred to as working grounding. The neutral point of the power supply (generator or transformer) is grounded directly (or through an arc-suppression coil), which helps to maintain a constant voltage between the non-faulty phases and ground. The neutral point of the primary winding of the voltage transformer is also grounded, ensuring the accuracy of voltage measurements in the primary system. The grounding of lightning protection equipment serves to allow lightning current to be discharged into the ground in the event of a lightning strike.
Generally, the neutral point of the system is directly grounded, which is known as working grounding. The wire that comes from the three windings of the transformer is also called the neutral wire or zero wire, and this point is referred to as the neutral point. Working ground means grounding the neutral point of the transformer. Its main function is to maintain the stability of the system voltage, that is, to reduce the risk of overvoltage in low-voltage systems caused by issues such as one-phase grounding or short circuits between high and low voltages, and it also prevents insulation breakdown
Working grounding refers to directly connecting a certain point in the power system (such as the neutral point) to the ground, or connecting it to the ground through devices such as arc suppression coils or resistors; this includes the grounding of the neutral points of transformers and instrument transformers.
Working ground can reduce the contact voltage on the human body, quickly cut off the power supply, lower the insulation level of electrical equipment and transmission lines, and meet the special requirements during the operation of electrical equipment.
Protective grounding, shielding grounding, lightning protection grounding, operational grounding
Work grounding includes: signal circuit grounding, shielding grounding, and intrinsically safe instrument grounding. Its purposes are to provide a potential reference point, suppress interference, and ensure explosion protection, among others
In normal and fault conditions, grounding at certain points in the power system to ensure the safe operation of electrical equipment is called service grounding. Working ground can reduce the contact voltage on the human body, quickly cut off the power supply, lower the insulation level of electrical equipment and transmission lines, and meet the special requirements during the operation of electrical equipment.