This paper combines the rules and characteristics of China’s rural electric shock, proposed rural power low-voltage safety protection should be used, and focuses on the quality of leakage protection measures to track and enhance operational management.
Keywords leakage protection configuration tracking the quality of operation and management
After the transformation of rural power grids, the management of the county department of rural low-voltage electrical power grid extends to household energy meter, safety problems they face, mainly in rural areas of personal injury and electric shock accident burn household appliances. How to improve the level of security of electricity in rural areas to a new level, is an important research topic is urgently needed.
A rural electric shock regularity and characteristics
Learned from years of operating experience, regular electric shock mainly in the following aspects:
1.1 in rural areas than in urban electric shock
Although the level of security of electricity increased year by year, to electrocution accident rate is still much higher than the world’s developed economies. Electric shock accident occurred mainly in rural areas, rural electric shock is the city’s six times. The main reason is: poor rural electricity, electrical equipment and the installation is not reasonable simple, low level of technology, management is not strict, farmers lack knowledge of electrical safety.
1.2 low-voltage electric shock than the high-pressure electric shock
It is not easy to contact high voltage grid; low-voltage network coverage, electrical equipment and more, so also many opportunities for people to touch; coupled with inadequate facilities, poor management, people thought paralysis, lack of knowledge of electrical safety personnel the opportunity to contact more.
1.3 electric shock seasonal
Every year from June to September is the electric shock of high season, mainly due to summer and autumn rainy and humid, electrical equipment insulation degradation; the hot weather, most people do not like to wear clothes and use insulated protective gear, and the body sweating, skin resistance decline. In addition, a time when the busy season, rural electricity consumption increases, people contact and operation of electrical equipment the opportunity to significantly increase the adverse conditions, coupled with careless subjective, has become highly concentrated electric shock season.
Electric shock 1.4 point multiple sites
Single-phase electric shock more than two phases (refers to the relative phase) electric shock, and the accident point occurred in the branch line, then the family line, climb wire, connectors, lamp, plugs and sockets, electrical switches, electrical controls, fuses, etc. . These are the people easily accessible location, but also prone to short circuit, grounding and leakage.
Rural electric shock reasons 1.5
1.5.1 Equipment failure
Low voltage overhead line is too low, on the ground height, distance from the building does not meet code requirements; Low pole cable fixed position is unreasonable, bad process, nor standoff insulators; with scrap wire or wire for wire; connector failure; electrical equipment metal ungrounded or poorly grounded; wire breakage or aging insulating layer as into the family line or electrical wire; broadcast lines and power lines installation distance does not meet the requirements resulting from each other take even; screw caps and bulb does not meet the standard requirements, and the zero line, phase lines are wrong, so that the bulb exposed metal screw charged; wrong-way switch connected to the zero line, so long live the lamp and so on.
1.5.2 Equipment disrepair
Then family line, lead to aging or damaged insulation; pole cable corrosion, lead off shares and aging joints, causing the break down lever; electrical damp, insulation aging; protect ground or zero line shell is broken; rubber insulated wire guard sets, flexible cable sheathing and insulation breakdown, flexible cable connector insulation wrap improper selection or loose material off; open load switch (plastic cover gates), lamp and socket insulation shields, etc. cover lost or broken.
1.5.3 Illegal operations
Lap live power lines or repair electrical equipment; not cut off the power, live mobile leakage fault electrical equipment; overhead line below or lifting equipment nor the security building measures; while the power supply of the machine, without authorization to work in the power equipment; violation of safety regulations, were parked around the isochronous transmission.
1.5.4 Private pull random access, illegal use of electricity
A line attached to lighting; directly linked with a wire hook overhead power lines; kangaroo grid electric fish, electric rat; hauled climb with old wire line down the middle lines.
1.5.5 lack of knowledge of safe use of electricity
Mired bare live wires falling off, bare drag electric shock; the three-hole or four-hole plugs, sockets very misconnection protection in phase line, causing the electrical equipment enclosure charged; Gordon climb poles or transformers; arbitrarily put the knife switch the ground running; non-insulating material wrapped wire connectors or breakage; the plug with a wire directly connected to the power line; damp places safe voltage electricity is not used; freely operate energized equipment.
1.5.6 do not install or use inferior leakage protector leakage protector
Agricultural Improvement former home security installation rate is very low leakage current is generally larger rural power circuit used current-total security mistakenly much action, and the action leakage current setting value is too large to protect the personal safety. Agricultural Improvement home security after installation, although the rate of increase may be a lot of fake and shoddy products into the rural power network, rural electric shock casualties continue to occur.
1.6 rural overhead lines, then the family line, temporary power line electrocution accident
According to statistical data analysis, overhead lines in rural areas, then the family line, electric shock accident occurred on a temporary power lines as high as 70%. In many factors in electric shock, electrocution accident caused by only one factor less than 10%, with more than 90 percent of electric shock is composed of two or more factors. Therefore, strengthening education management and electrical safety electrical safety knowledge is very important.
It should be noted that in the rural power before and after rectification, the law may change with electric shock. We should be in practice, constantly analyze and summarize its laws, to provide a reliable basis for the development and improvement of safety measures to improve security of electricity.
2 leakage protection configuration and selection
We should combine the status of rural low-voltage grid, it is necessary to achieve the safe protection work, reduce electric shock, but also improve the reliability of the power grid, which is a comprehensive requirements for the protection of the proposed cut leakage. Facts have proved that: the use of hierarchical protection leakage protection is the fundamental way to achieve these requirements, but also the inevitable trend of development of leakage protection. According to our low-voltage power supply grid, economic conditions and production leakage protection, etc., the use of low-voltage power grid in bipolar leakage protection approach is feasible, and it is most effective.
First, should increase the final stage of the installation rate of leakage protection and put into operation rate, the last stage shock protection to prevent direct contact with the main objective to protect their small plane, does not interfere with other users. Urban and rural families into the family line of contact and the widespread use of portable electrical equipment, power tools, etc. should be the choice of the rated residual operating current is less than 30mA of high sensitivity, fast leakage protector. For single-phase electricity customers should choose the leakage protection with over-voltage protection function, when used to prevent the emergence of the total three-phase four-wire neutral wire is disconnected and then family miswired into 380V line voltage, resulting in abnormal overvoltage damage appliances. The best selection with leakage, overvoltage, overload protection and short circuit protection, so that all the anomalies of single-phase electricity customers can be protected. To cause secondary injury after a shock sites, such as aerial work or electrical equipment used in the river bank, can be installed leakage current for fast leakage protector of 10mA.
The second level of protection for total protection or branch protection systems. This level of protection can be installed in each branch or head-end line of low-voltage distribution transformers at the outlet, its scope of protection for the trunk (or branch line) low-voltage grid, under the family line and into the family line, but also as an end backup protection level of leakage protection. Rated residual operating current should be determined according to the protected line and the actual leakage current equipment.
This two-stage trigger leakage protection constitutes a leakage protection network classification, first-class protection against the harsh conditions and some of the higher risk of electric shock provides protection where direct contact; a second level of protection is to expand the coverage of leakage protection, improve the overall safety level of low-voltage grid. Between the two levels of protection should be reasonably fit, its leakage current and operating time should be differential. Proposed to consider the higher rated leakage protection leakage current of 2.5 to 3.0 times the rated leakage current to the next level, the level of leakage protection operating time of the lower level of a movement to increase the operating time differential, around about 0.1 ~ 0.2s .
3 leakage protection quality tracking
Leakage protection as a national mandatory implementation of safety certification of electrical products, its quality is directly related to the merits of the user’s life and property safety, for quality of leakage protection has been a problem of concern to the user. Especially the rural network “two reform” since the work carried out, the surge in demand for leakage protection, stability of many quality, good performance, full-featured extensive leakage protection chosen by the user, but there are a lot of poor quality agricultural products into the net. Hence the need to strengthen and carry out supervision of the quality of leakage protection, dynamic management, improve the quality of consciousness production operators to prevent substandard and counterfeit products into the low-voltage grid. Now how to strengthen and standardize the conduct some suggestions on the quality of regulatory leakage protection:
(A) insist on the implementation of safety leakage protection conformity certification, mandatory supervision and management is to ensure the quality of the premise and foundation. From a few years to track the quality has made the security situation on the certificate of conformity of the product, the stability of product quality was better than not been certified products, indicating that qualified to carry out safety certification for the future quality of the product has an important role .
(2) to carry out leakage protection quality tracking and supervision is effective measures to promote and ensure product quality. Carry out leakage protection is to track the quality of supervision and implementation of dynamic regulation of its quality, and thus judge its quality status, therefore, leakage protection quality tracking and supervision is carried out on the quality of regulatory leakage protection key areas. Leakage protection for tracking the quality of the main aspects of work should do the following:
1) quality assurance oversight bodies sampling track testing and technical assessment authority. Verification testing capabilities to track the quality and reliability of the assessment of supervisory authority is qualified, will directly affect its accuracy in tracking product quality assessment, therefore, to ensure the quality supervision authority is to carry out a key quality tracking supervision.
2) further increase the quality of supervision of certified products tracking efforts, quality tracking supervision should adhere to the “Three” (fair, just and open), “three unification” (unified supervision standards, unified supervision approach, unified test items) principle, quality assurance tracking supervision seriousness. Supervision must be conducted with strict quality tracking and standardized work procedures, relevant information to track the quality of products and clear conditions to participate and businesses should provide open standards and technology assessment principles leakage project protection quality tracking test and used to announce sampling approaches and quantity. Such as Zhejiang Province leakage protection quality tracking test has been carried out for many years; Henan Province since 1999, first recommended to the provincial bureau grassroots counties user based on usage, commissioned by the provincial bureau review after testing organizations test qualification. Provinces ongoing quality tracking tests were conducted according to national standards, the selected item highlighted the main features of leakage protection.
3) timely disclosure of product quality testing, the detection of the products for their quality improvements are an important part of the quality of tracking supervision.
4) to detect the presence of defects in the quality of products, quality improvement after making periodic retesting is tracking supervision is another important part of the quality. It is to promote the products of the manufacturers of quality defects effective measures to improve product quality, but also reflects the manufacturer’s production, technology and quality management. Such as the existence of quality defects, Zhejiang Province of detection products, improvements in the quality of the proposed 3 to 6 months after a random sample retested and re-examination of the case published quality.
(3) enhance the legal concept, adhere to the use of legal conduct quality control, leakage protection is also an important way to ensure quality.
Enhance and improve the legal awareness of quality control department and production operators is to carry out legalization, the foundation and prerequisite for the standardization of Quality Supervision, which is directly related to the quality of supervision can make the law, whether to use legal means to protect the reputation and the use of qualified products owner’s equity, therefore, insist on relying on the quality of regulatory laws to promote product quality has a very effective role. Quality supervision departments to remind and warn the user preferred brand of qualified products to protect qualified production enterprises, while preventing and combating counterfeit products. In addition, the quality of leakage protection and legal responsibilities and linked, such as the forthcoming local regulations, Zhejiang Province “Zhejiang physical shock compensation approach”, it has been clear to endanger the safety of electrical products business will legal liability, leakage protection is one of them suggested that the state should put the appropriate regulations.
(4) enhance the quality and timely feedback, and increase investment in science and technology is an important means to enhance and ensure the quality of products.
Quality control department and using the administrative departments should strengthen the already put into operation the leakage protection monitoring quality of service and business surveys and feedback, timely leakage protection operation and the quality of feedback to producers. Actively support and encourage enterprises and research institutions to develop new products, and constantly improve the leakage protection function.
(5) recommended the establishment of the National Association of leakage protection, and specify the test conditions have to enter the rural power unit leakage protection manufacturer’s product sampling test every year, and announced the recommended manufacturer and product type, product quality, price, service and other comprehensive supervision is necessary to prevent counterfeiting, and shoddy products into the rural network, but also against unfair competition from low-price, low quality.
4 leakage protection operation management
To install leakage protection due to play a protective effect, it is necessary to strengthen the operation and management of the grid, the power sector at all levels should pay attention to this work. Especially in the rural power during and after the rectification, maintenance and management of the county department of electrical household meter to farmers, prompting them to relevant safety issues must vigorously strengthen management. Below the provincial electricity sector at all levels, including the township (town) powered by, should be equipped with special (and) the security personnel on the grid and leakage protection management. The use of units in the selection of a particular product, deal with the product’s features and performance testing prior to use, and only after functional performance testing of products before they allow the installation to the scene. Each county departments should be equipped with the necessary power test equipment and qualified professionals to ensure the implementation of this measure. At the same time should be set up or slice up a separate leakage protection maintenance, to ensure that the damaged leakage protection can be repaired in a timely manner. County and township power sector should periodically sampling leakage protection operation. End-stage leakage protection assets belong to the user, the power sector has a responsibility to promote, guide, inspect, supervise its installation and accelerate the popularity, to ensure the quality, ease of management, conditions can be unified procurement, installation, with household filing. The total leakage protection is the power sector assets should be used and put into operation rate, with the final stage of protection can reasonably meet the total leakage (branch) protector. Each total leakage protection device installed and put into operation, the responsible person should run clear, with a trial jump run record, commissioning test cases recorded correctly, try to jump on a regular basis, the operation of the trip, the recovery time of transmission, the cause and abnormal and so on. County and township-powered electricity sector should be equipped to leakage protection performance of field test instruments, the organization of rural electrician training. Township powered by organizations with annual actual station area and drain leakage current overall protection performance once the field test, make a record, evaluation, in order to ensure the total leakage protection is in good condition.
Leakage protection for installation, operation, each county under the jurisdiction of the power sector to respond powered by township and users make the following provisions:
(1) requires each unit of electricity by households and leakage protection required to be installed, otherwise it will not supply.
(2) Where the newly installed leakage protection must meet national standards, national certification mark, its technical parameters can be protected equipments. Shall purchase and install substandard products.
(3) leakage protection tripping coincide unsuccessful, the reasons must be identified before delivery after the elimination of fault current, are not allowed to force transmission, not energized unprotected state.
(4) No person shall use any excuse to dismantle the unauthorized leakage protection or out of operation, or not powered by the removal of those responsible for all the consequences.
(5) For the breach caused personal injury, equipment damage who, depending on the seriousness of the case, were given criticism and education, punishment until the criminal prosecution.
Installation of leakage protection, run the following information should be required to collect, aggregate, save and reporting:
(1) powered by township should establish total leakage protection ledger, the final stage leakage protection statistics and ensure consistent with the scene. Six months or a year, once aggregated, summarized subjects should include: each station area with variable number of units, the number of lines of low pressure, leakage protection units installed and put into operation the number, type, manufacturer, date of manufacture, the township, the total leakage protection installation rate, replace damaged several units, the number of new units, the final stage leakage protection the number of units and installation rate. A summary table at the county level power sector, a long-term storage on file.
(2) powered by township monthly total protection to deal with leakage test run and jump record summary. Subjects summary should include: various models leakage protection units total number of trips and the number of permanent failure, the cause classifying, summarizing record twelve months in a year will be aggregated, summarized in a report the county the power sector, a stay stalls long-term preservation.
(3) powered by the township to annual total leakage protection performance test records a summary, summary subjects should include: various models of the total leakage protection device rated residual non-operating current substandard number of units, the number of units operating current exceeding the rated residual operating current operating time exceeded the number of units under, phase amplitude type of action should be to increase the rated current of electric shock is not unqualified number of units, the operating time under rated operating current shock exceeded the number of units, number of units, such as blocking function failed. Field notes generally kept for three years, in order to facilitate comparison of before and after. A summary report on the county the power sector, a stay-speed long-term preservation.
(4) Upon receipt of the county and township in the power sector should also report summary report municipal electricity sector, municipal power sector should receive a summary report at the provincial bureau reports the county, provincial, city and county should lower the long-term preservation News reports and summary tables come. Thus, to fully grasp the power sector at all levels of leakage protection status, operations analysis and problems, provide a reliable basis for decisions of higher authorities.
In addition, when leakage protection within the scope of protection of human casualties, the former accident investigation should protect the scene, not dismantled leakage protection. Electricity leakage protection departments should check the performance conditions and the implementation of regulations, such as leakage protection features, performance is normal, can not ignore the existence of leakage protection dead zone, such as phase and phase by phase zero occasionally shock possible. In order to improve the leakage protection of personal electric shock protection security, while ensuring the reliability of supply, leakage protection in addition to strengthening the management itself, the need to strengthen the management of low-voltage power grid, so as to enable the transformation of rural power equipment levels and after security level there is a qualitative leap.