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1, outdoor lighting leakage protection can not be ignored Were electrocuted when the severity of the harm suffered by persons related to the size-frequency current. A large number of tests to prove: one ventricular fibrillation caused by electric shock when the phenomenon, not only through the human body current (I), but also with the current duration (s) concerned. When the battery is 50mA? S, generally does not cause ventricular fibrillation, but the human body through a short high current (eg 500mA × 0.1s), there is still the risk of causing ventricular fibrillation, although not fatal, it may shock those who loss of consciousness, caused by the secondary injuries. Kebin proposed security capacity Q = 30mA? S of the set is: "that the current through the body of less than 30mA? S, who would not hurt." General, switches, circuit breakers, fuses and other circuit or load can overload, short circuit failure cut off power supply, the protection of electrical installations will not damage or fire. However, facilities such as poles and other electrical leakage fault occurs, still fail to switch, circuit breakers, fuses and other protection facilities of the action current value, then touch the person who caused due to leakage or ground poles and other charged objects still sufficient to cause injury or fire. Metal lamp posts outdoor lighting, lamps, transformers, power distribution boxes are located mainly in public places, people can easily come into contact with it, in case of leakage failure to extremely serious consequences. Therefore, the outdoor lighting system is necessary to set leakage protection device. After the installation of earth leakage protective device, should continue to focus on prevention, and should also take other measures to prevent the electric shock and damage to electrical equipment, technical measures. Present, road lighting and road lighting generally in accordance with the TT power distribution system design and installation; facade lighting, stadium lighting in accordance with the TN-S system design and installation, has a certain security. However, in some adverse conditions (such as the occurrence of leakage and ground lighting metal damage), the possibility of injury due to light leakage still exists. Therefore, it is necessary to take seriously the issue of outdoor lighting leakage protection. 2, outdoor lighting and lamps line the leakage current Lighting outdoor lighting is characterized by long lines, a lighting circuit then several sets of lights. Only know the lighting circuits and lighting of the leakage current in order to have a good chance to adjust the action current leakage protection value. Learn lighting circuit and leakage current methods are three kinds: (1) of the existing lighting circuit with lamps measured leakage current values, this is more accurate but also quite complicated; (2) estimates of line and light leakage current: three-phase and single-phase cable line leakage current of about 22mA/km; light leakage current about 1 mA / set; (3) look-up table calculation of three-phase and single-phase cable line of the leakage current values shown in Table 2. 3, the action current leakage protection After electric shock accident may result in serious secondary site, use the quick action 6mA current leakage protection device; Fountain, swimming pool, bathhouse, pool lighting or electrical equipment inside, used for the 6 ~ 10mA operating current rapid leakage protection device; For Class I hand-held power tools, should be considered dangerous nature of their workplace size, the installation is 10 ~ 30mA operating current rapid leakage protection device; Electrical equipment installed in damp places, such as, leakage protection device operating current should be 6 ~ 10mA; Appliance circuit: current leakage protection action 30mA; Rated voltage 220V or 380V fixed electrical equipment such as pumps, motors, etc., when the shell is less than or equal to the grounding resistance 500 , the stand-alone configuration of action current leakage protection should be 50mA; Electrical equipment to prevent burnout, and to a certain degree of reliability, power, leakage protection device operating current should be 100mA ~ number of amps (A). Large electrical equipment or electrical equipment have multiple power lines, grounding resistance when the shell is less than or equal to 500 , the leakage protection device operating current should be 100mA; Grounding resistance when the shell is less than or equal to 100 , the leakage protection device operating current should be 300 ~ 500mA. 4 outdoor lighting leakage protection 4.1 leakage protection requirements Leakage action current of 30mA and less leakage protection device can be used as direct or indirect protection of the human body; leakage action current of 300mA and higher leakage current device to prevent cable damage and aging as a result of fire caused by earth leakage protection of fever. Leakage protection setting value, that is rated residual operating current required to escape the lines and facilities the value of the normal leakage current. 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