Can the problems of frequent tripping and failure to trip of the residual current device not be resolved?

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During the transformation of these two power grids, residual current operated leakage protectors were widely used. Over the years, it has become evident that the damage to such protectors and the intentional disabling of their operation are serious problems. The problems of power consumption losses and safe electricity use remain severe. The reasons for this are multiple, but the direct cause is the frequent malfunctioning or failure to operate of the leakage protectors, which severely affects normal power usage. As a result, those in charge of electrical systems and users lose confidence in leakage protectors and even give up on using them. The tripping of residual current devices involves two aspects: 1. When there is indeed a ground connection in the power grid, the residual current device operates normally. In such normal operations, trips are caused by ground points that arise due to the aging of the power grid or changes in climate conditions; trips caused by electric shock to people are extremely rare. It is conceivable that having access to electricity is people’s top priority; frequent power outages, caused by trying to prevent the extremely rare occurrence of electric shock injuries, would certainly cause trouble by disrupting normal production and daily life. 2. The power grid itself is not grounded; instead, the leakage protector may operate erroneously under the following conditions: ① Since the leakage protector is activated by signals, other electromagnetic interferences can also generate signals that trigger the protector to act, resulting in erroneous operation. ②When the power switch is closed to supply power, an impulse signal is generated, causing the leakage protector to operate erroneously. ③The sum of leaks from multiple branches can cause false tripping at a higher level. Digital meters: yunrun.com.cn/product/ ④ Repeated grounding of the neutral wire may cause erroneous operation due to stray currents. It can be seen that, due to these technical possibilities of false trips in leakage protectors, the problem of frequent tripping of such protectors becomes even more severe and complex. From a technical perspective, circuit breakers with leakage protection can also suffer from technical flaws that lead to failure to operate. 1. When repeated grounding occurs on the neutral wire, it can cause the leakage protector to fail to operate due to current diversion, and the location of such repeated grounding points on the neutral wire is very difficult to identify. 2. When there is a missing phase in the power supply, and that missing phase happens to be the power supply for the leakage protector, this will result in failure to operate. From the above analysis, it can be seen that the problems of frequent malfunctioning and failure to operate that occur in residual current devices in actual use are due to both objective environmental and management factors, as well as technical flaws in the devices themselves. In particular, the use of residual current devices requires that the neutral point of the power grid be grounded, and most technical misunderstandings related to residual current devices are associated with the grounding of the power grid’s neutral point: 1. Due to the grounding of the neutral point, the conductors in the power grid are under the influence of line voltage throughout the year, which causes these conductors to break down and form grounding points in the power grid, leading to leaks and triggering frequent activation of the residual current devices. 2. Due to the neutral point being grounded, when a phase wire comes into contact with ground occasionally, a large leakage current is generated immediately. This not only increases electrical losses and increases the risk of fires, but it also exacerbates the frequent tripping of the leakage protector. 3. Due to the grounding of the neutral point, when a person comes into contact with electricity, a large electric current is generated immediately, posing a serious threat to life. Even with a leakage protector, the person is struck by electricity first before the protector can activate to provide protection; if the protector responds slowly or fails to function, the consequences will be even more severe. Changhui Instruments yunrun.com.cn/ 4. Due to the neutral point being grounded, the distributed capacitance of the power grid with respect to the ground is connected in the circuit, which increases the inrush current to the ground when the switch is closed, leading to accidental operation. 5. Since the neutral point is already grounded, repeated grounding of the neutral wire is difficult to detect. Repeated grounding of the neutral wire can cause the leakage protector to fail to operate due to current diversion, or to operate erroneously due to current coupling. It is evident that there are indeed technical misunderstandings regarding leakage protectors, and these misunderstandings are closely related to the grounding of the power grid’s neutral point. Moreover, when using leakage protectors, it is necessary to keep the power grid’s neutral point grounded; therefore, it is hardly possible to resolve issues such as frequent malfunctioning or failure to operate these devices within their technical design framework.