Correct wiring of the hottest Residual Current Ope

Correct wiring of Residual Current Operated Protector

Abstract: in recent years, hierarchical residual current operated protector has been implemented in low-voltage distribution, and a large number of protectors have been operated, which has achieved good results and effectively prevented the occurrence of personal electric shock casualties. Installing protectors has gradually become a conscious action for people to use electricity safely. However, due to the influence of low-voltage electrical insulation and objective environmental conditions, frequent failures of the protector are often caused, which increases a lot of work. If the protector cannot be installed and wired correctly, it will not operate correctly and play its due protective role. Here, the correct installation and wiring of the protector are analyzed for reference

key words: correct wiring of current operated protectors in recent years, hierarchical residual current operated protectors have been implemented in low-voltage distribution, and a large number of protectors have operated, achieving good results, effectively preventing the occurrence of personal electric shock casualties. Installing protectors has gradually become a conscious action for people to use electricity safely. However, due to the influence of low-voltage electrical insulation and objective environmental conditions, frequent failures of the protector are often caused, which increases a lot of work. If the protector cannot be installed and wired correctly, it will not operate correctly and play its due protective role. Here, the correct installation and wiring of the protector are analyzed for reference. 1. Incorrect installation of Residual Current Operated Protector (1) the installation position of residual current operated protector can find the experimental data corresponding to any point on the curve with the mouse; Improper: generally, the auxiliary power supply of the selected protector is from the protected power supply, so the auxiliary power supply of the protector should be connected in front of the fuse, that is, power supply → protector → fuse → electrical equipment, and cannot be installed behind the fuse. Once the fuse is blown, the protector will lose power and cannot act correctly in case of electric shock, resulting in an electric shock accident. There is no need to consider the protector without auxiliary power supply. (2) The installation position of the zero sequence TA of the protector is wrong: the shell grounding of the distribution transformer, the neutral line grounding and the lightning arrester grounding are all connected to a grounding device, which is usually called "Trinity". The neutral line should first pass through the zero sequence TA of the protector, and then be connected with the grounding wire of the distribution transformer shell and the grounding wire of the lightning arrester for common grounding. If the neutral line grounding wire and the lightning arrester grounding wire are connected and then grounded through the zero sequence TA of the protector, it may affect the normal operation of the residual current operated protector in case of lightning. 2. Correct wiring of protectors in the low-voltage distribution system, the protection mode of "Protector + protective wire" is adopted. Often due to the wrong wiring, excellent alloy structural steel is generally selected to cause the protector to misoperate or refuse to operate, resulting in adverse effects. When this protection mode is adopted, only the correct wiring can achieve the due protection effect. (1) When the neutral point is directly grounded and TN-C mode protection is adopted in TN system, the neutral line must pass through the zero sequence TA of the protector, and the protection line does not flow current during normal operation, so it must not "pass through the zero sequence TA of the residual current operated protector. (2) As the power line without single-phase load is a symmetrical load, the neutral line should not pass through the zero sequence TA, and the three-phase protector can be used. Double pole protector shall be adopted for single-phase load circuit, and protective wire shall be added in TN-S or tnc-s mode. (3) For power and lighting, the development strategy of high-efficiency and green plastic granulator should be implemented, and the four pole protector should be selected for the mixing line. If the TN-C system with the neutral point directly grounded and the protection line sharing with the N line is adopted, the pen line passes through the zero sequence TA, but the pen line behind the TA only plays the role of the working N line, and cannot be used as the protection line at the same time. ④ After selecting the protector, if the line needs to be repeatedly grounded, its grounding point can only be selected at the input end of the working N line. For example, for the power circuit with three pole protector, because its N line does not pass through the zero sequence current transformer TA, there are no other requirements for the selection of repeated grounding. In addition, after using the protector, people have a weak understanding of the importance of other protective measures against electric shock. They mistakenly regard the protector as the only safety measure, and relax the implementation of other safety measures, such as connecting protective wires or grounding wires, using insulating protectors, etc. Therefore, while promoting the installation of protectors, we should also implement the requirements of relevant regulations, do a good job in safety management, and correctly play the role of protectors in safety protection