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A short circuit refers to direct contact between phase wires or between a phase wire and the neutral wire; the current that results is known as the short-circuit fault current. Because the resistance at the short-circuit point is very low, the line impedance is also very low, so the short-circuit current is large. In IEC standards, a short circuit between a live conductor and ground is referred to as a “ground fault”. Ground fault includes fault conditions that arise from damage to the insulation of electrical devices, as well as those that occur when the exposed conductive parts of electrical equipment come into contact with the housing. When the exposed conductive parts of electrical equipment have a fault voltage with respect to ground, an electric shock suffered by a person who comes into contact with this fault voltage is known as indirect contact electric shock. The difference between short circuits and ground faults: yunrun.com.cn/tech/2897.html Let’s take a look at Figure 1. http://yunrun.com.cn/upload/202002/01/202002012213553081.png Figure 1: Difference between short-circuit faults and ground fault faults. From Figure 1, we can see the difference between short-circuit faults and ground fault faults. The “ground” referred to here is the exposed conductive parts of electrical installations, or the metal structures and pipes within a building, including the earth itself. Indirect contact electric shock accidents caused by ground faults are the most common and frequent type of electric shock accidents. The “Electrical Fundamentals” section on Changhui Instrument Network shares many useful articles; those who are interested can take a look. Indirect contact electric shock is caused by grounding faults, and the protective measures vary depending on the type of grounding system. Some of the protective measures against indirect contact electric shock are incorporated into the product design and manufacturing of electrical equipment, while others are added during the design and installation of electrical installations; in other words, the protection against indirect contact electric shock is achieved through a combination of electrical equipment design and electrical installation design. Ground fault in low-voltage systems not only endangers the safety of low-voltage switchgear but also poses risks to human safety and the environment, potentially causing electric shock or electrical fires; therefore, protection against ground faults must be considered from the perspectives of electric shock protection and electrical fire prevention.