Electrical safety knowledge constant detection of electrical hazard factors and accident type i, electrocution 1, divided into electroshock and electrical injuries. 2. Electricity shock current values: perception current averages 1. 1ma for males, 0. 7ma for females, 16ma for males, 10. 5ma for females and approximately 50ma for room tremors, relating to duration. Human resistance: approximately 10003,000 when dry and 500,800 when wet. 3. Type of electroshock: depending on whether the body with which the electroshock is touched is in a normal state of electrical charge, it is divided into direct and indirect exposure to electroshock; it can be divided into single-phase electric shocks, two-phase electric shocks and cross-step electroshocks, depending on the manner in which the body touches the body with the electroshock. Single-phase electric shocks accounted for more than 70 of all electrocution incidents. 4. Electricity injuries are thermal, chemical, mechanical, etc. Effects of electric currents. Electricity injuries include electric burns, branding, metalization of skin, mechanical damage, electrophotosis, etc
2 - harm. Electricity burns. It's the most common. Large local electrocution incidents all contain electrical burns. Electricity burns can be divided into electric burning and electric arc burns. Electrical fires and explosions1 and electrical fire explosions are fires and explosions caused by sources of electrical combustion. Hazardous temperatures, electric sparks and arcs generated by electrical installations in operation are the main forms of electrical combustion sources. 1 dangerous temperature: short circuits, overloads, power leaks, poor exposure, iron heart overheating, heat dissipation, mechanical malfunctions, voltage anomalies, electro-thermal and lighting devices, electromagnetic radiation energy. Two sparks and arcs: the sparks are interpolated by interpolar shocks and the arcs are concentrated in large quantities. They are divided into work and arc, accident and arc. 2. The explosion of electrical installations and circuits included an oil-impregnated transformer fire, an electrically motivated fire and a cable fire explosion. Iii. Thunder hazard 1, type of lightning, form of hazard and type of lightning as a consequence of an accident: direct
3. Each discharge process of a direct lightning strike consists of a lead discharge, primary discharge, three phases of residual light, and a flash sense that should include a lightning electrostatic sensor and a lightning electromagnetic sensor, and a ball thunder. The hazard forms of lightning are characterized by high-value, steep, shock-prone, shock-exceeding, and destructive effects of electrical, thermal and mechanical nature. 3 accidental consequences of lightning and electrical hazards: fires and explosions, electrocution, destruction of equipment and facilities, massive power outages. Thunder parameters: thunderstorm day, thunder flow magnificence, thunder flow voltage, thunder flow expulsion. IvStatic hazards1. The harmful forms of electrostatic power and the consequences of accidents cause explosions and fires, may cause secondary accidents and hinder production. 2. Electrostatic properties 1 electrostatic means of generation of exposure - insulation, break-up, induction, charge transfer, solid static, human electrostatic over 10,000 v, powder static, liquid static, vapour
4 and gaseous static. 2. Dispersion of static electricity: neutralization, leakage. 3 impact factors of electrostatics: materials and impurities, industrial equipment and industrial parameters. V. Radio-frequency electromagnetic field hazards refer broadly to electromagnetic waves with a frequency above 100khz. Hazard 1: the human body suffers varying degrees of harm from the absorption of radiation energy. 2. Production of sensor discharge caused an accidental detonation of the detonator. Vi. Types of damage to electrical installations: break-off, short circuits, abnormal patches, leaks of electricity, faulty locks, damage to electrical equipment or electrical components, etc. Hazards: fires and explosions, abnormally charged power, abnormally outages, safety-related system failure. Insulation: insulation of insulation material applied in engineering is generally not less than 107 m. Electrical resistance for insulation material is usually measured by a mega-eat rock. Insulation electrical resistance shall in no case be less than 1,000 work volts per volt. 2. Screen protection and spacing: 1 screen protection
5. The device shall be of sufficient size to maintain the necessary distance from the carrying body. The height of the shield should not be lower than l. 7 m and the lower edge should not exceed 0. 1 m. The height of the fence shall not be less than l. 2 m, the outdoor space shall not be less than l. 5 m and the distance between columns shall not be greater than 0. 2 m; for low pressure devices, the distance between the barrier and the naked conductor shall not be less than 0. 8 m. The height of an outdoor transformer fence should not normally be less than 2. 5 m. Covers, fences, etc., should be marked with "stopping, pressure danger! " 3. Spacing between electrical devices: a visible workshop low-pressure distribution tank at a height of 1. 2 m above the ground floor and a blackout of l. 4 m. The height of the surface at the bottom of the clearly charged table is 1. 8 m. The installation height of the commonly used switch appliances is l. 3l. 5 m; the distance of 150 mm between the switch handle and the building should be preserved for ease of operation. The walls are flat
6. Levels above ground are 1. 4 m. Clear plugs are 1. 3l. 8 m above ground altitude and 0. 20. 3 m in cover. Indoor lamps shall be at a height greater than 2. 5 m; they may be reduced to 2. 2 m if the actual conditions are not met; and appropriate safety measures shall be taken when less than 2. 2 m. When the lamps are located above the desktop, they are not accessible to people, and the altitude can be reduced to 1,5 m. Outdoor lamps should be above 3 m; they can be reduced to 2. 5 m when installed on walls. The minimum distance between cranes and route guides shall not be less than 1. 5 m for lkv and less than 1 kv, and not less than 2 m for 10kv. 4 spacing: in low pressure operations, the distance between the human body and the tools it carries and the electric body should not be less than 0. 1 m. For high-pressure operations, 10 kv should not be less than 0. 7 m between the working body and the vehicle with which it is carried; and for line operations, 1. 0m. Ii. State
7. Exposure to electroshock protection measure 1 and protection of the it system places the part of the metal where electrical equipment may exhibit dangerous voltage in case of failure, closely connected to the ground. Limiting failure voltage to safety through low electrical resistance; in 380v non-terrestrial low voltage systems, protection of ground resistance re4 is generally required; and for various off-site distribution grids. Tt systems: the distribution grid is directly connected to the ground and electrical equipment is shelled to the ground. The failure voltage on the leaking equipment shall be substantially reduced, provided that the remaining flow of electricity shall be protected or the excess current protection shall be installed. The job site is not a secure voltage. Mainly for low-pressure users, i. E. For small users who are not equipped with electrical transformers to introduce low-voltage power sources from outside. 3. The tn system protects zero electrical equipment by direct connection between the non-electrical part of the metal and the neutral point of the distribution grid. It is equivalent to a traditional zero-protection system. First of all, the peace is swift
8. Cut the power. These are tns, tncs, tnc. Tns systems perform the best in safety and are applied to sites with high explosive risk, high fire risk and other safety requirements. The plant's low-voltage distribution sites and civilian buildings should have a tncs system; the tnc system could be used in cases where electrical exposure is low and electrical equipment is simple. The protection of zeros is used in the distribution grid of the 220380 v-trill four-line distribution network of the low-pressure neutral point where the user is equipped with electrical transformers. Application of safety requirements: 1) in the same zero-to-zero system, local or individual equipment is generally not allowed to be located only and not zero; 2) repeat repeat location. 3) a single-phase short circuit of the pe line can be quickly cut off. Tn systems, hand-held electrical equipment and short-circuit protection elements for end-line or interpolation circuits for mobile electrical equipment, for 220 v, to ensure that failure duration does not exceed 0. 4 s, distribution line or fixed electrical
The end-line of the equipment shall ensure that the duration of the failure does not exceed 5 s. 4) qualified place of work. Ground-based resistance should generally not exceed 4 and not exceed 10 in areas with high soil resistance rates. 5) pe and pen lines shall not be fitted with unipolar switches and smelters; pe and pen lines shall be protected against mechanical damage and chemical corrosion; pe feeder lines shall not be linked, i. E. The exterior conductor parts of the equipment shall not be used as a protective conductor. 6) the protection of the cross-section area. Pe has a mechanical shield of not less than 2. 5 mm2, no machine of not less than 4 mm2; pen is not less than 10 mm2 for copper, not less than 16 mm2 for aluminium and not less than 4 mm2 for cable cores; sl 16 is sl, 16sl 35 is 16 and sl 35 is sl/2. 7-bit connection, primary level connection and auxiliary level connection. Iii. Measures against direct contact and indirect exposure to electric shock 1, dual insulation1 electrical set
Categorization of protection against electrocution: category o, oc and c, c, c. 2 dual insulation and enhanced insulation measures: insulation at work, protective insulation, dual insulation, enhanced insulation. Equipment with dual insulation and enhanced insulation is of the type and has a “return sign”. Work insulation is not less than 2 m, protection insulation is not less than 5 m, strengthening insulation is not less than 7 m. 2. Peaceful voltage: safe measures with both direct and indirect exposure to electroshock protection. 1 lvpv limit and rated values: 5 grades: 42v, 36v, 24v, 12v and 6v; equipment supplied by lvpv is classified as equipment; the rated values are selected for: specially hazardous environment handheld tool 42v, click on dangerous environment handheld light 36v or 24v, metal containers, especially wet and dangerous environment handheld light 12v and underwater 6v. 3. Protection of residual power flow, also known as leak protection, and effect: prevention of physical shock and exposure to ground failure
Fires were fired and a series of site failures were monitored. 1 working principles. (b) the elements for detection, the intermediate, the three fundamentals of the implementing agency and the composition of the auxiliary power supply and the test device. 2 main technical parameters: rating of remaining movement currents, rating of remaining non-action currents, break time. The remaining mobile current values are rated at 13 levels, 0. 03a and below are highly sensitive and are used primarily to prevent various types of physical contact; 0. 03a and above 1a are medium-sensitivity to prevent electrical contact and leaks; and 1a and above are low-sensitivity to prevent electrical leakage and to monitor side-by-side accidents. The rated residual non-activated current may not be less than 12 of the rated residual movement current. The break-up time is divided into a general and a delay type, which only applies to indirect contact shock protection in in>003a, with a difference of 02s for the delay time. The remaining electrical flow is required to protect the protective devices. In the tn system, you have to use tn
12, c systems may only be installed after conversion to tncs, tns or local tt systems. In the tncs system, the remaining electrical flow is protected only in parts of the n-line separated from the pe-line. Equipment and sites for the remaining electrical flow protection units must be installed. 1) end-of-pipe protection of mobile electrical equipment belonging to category i; electrical equipment for production; electrical machinery for construction sites; electrical devices installed outdoors; electrical equipment for temporary electricity; electrical outlets or circuits for power sources other than walled air-conditioning power outlets, such as institutions, schools, hotels, restaurants, enterprise units and homes; electrical equipment for swimming pools, fountains, baths; electrical medical equipment for which there may be direct contact with the human body in hospitals; and other. 2) lines protect rural areas from centralized installation of electrical meters; power distribution tanks for agricultural production equipment. The remaining electrical flow is operated and managed as a protective device. Six years of service and one call allowed。
13; electrical fire protection and detonation technologies i; classification of hazardous substances and hazardous environments as hazardous substances, cluster 1; classification of hazardous substances as explosive hazardous substances, category 3: methane from mine mines, explosive gases, vapours, explosive dusts, fibres, ejection. Category 2, category c, category c explosive gases are further classified into categories a, b and c, which are the most dangerous, according to the maximum test gap and the lowest flammable current ratio. Grouping of 3 classes, classes, classes of explosive substances: 6 groups according to the induction temperature. Sub-areas of hazardous environment 1 and explosive gas environment 1 the frequency and duration of occurrence of explosive gas mixtures are divided into sectors 0, 1, 2. Levels of release sources and ventilation conditions have a direct impact on the zoning. The main types of ventilation are natural and artificial, and the effectiveness of ventilation is divided into “good ventilation signs are hazardous substances in mixtures”
14. Concentrations are diluted below the lower limit of 25 blasts. General and “three levels different, iec and our standards divide ventilation into three levels, high, medium and low. 2 classification of hazardous areas in explosive gas sites: original. 3 range 2 of the explosive gas environmental hazard area, the explosive dust environment is divided into 20, 21 and 22 zones according to the frequency, duration and thickness of the mixture. 3. Fire risk environments are divided into 21 regions, 22 regions and 23. Type of blast-proof electrical equipment and blast-proof electrical circuit 1 and blast-proof electrical equipment 1 2 device protection level epl: ma/mb/ga/gb/gc/gc/da/db/dc3 explosive electrical equipment explosive protection structure type: detonation, emplacement, physical safety, sealing, fire free, positive pressure, etc. 4. Marking of explosive electrical equipment: the selection of electrical equipment in an ex5 explosive hazard environment:
Depending on the environment, type of equipment, etc. 2. The selection of the location, placement, conductor material, connection, etc. Of the explosive electrical circuits shall be based on the environmental hazard level. Area 1 distribution lines should be based on a copper core guide or cable, multiple copper core softlines or multiple copper core cables should be selected for severe vibrations, and aluminium core electric cables should not be used under mines. Area 2 power lines should use aluminum core guidance line or cable with an area of 4mm2 and above, and lighting lines may use aluminium core guidance lines or cables with an area of 25mm2 and above. Sectors 1 and 2 must have medium- and indirect headlines in the connector box, area 1 would be suitable for blast-proofing and area 2 would be enhanced. Mine-proofing and electrostatic protection technology i, mine-proofing measure i, mine-protected building type i powder manufacturing workshop, acetylene station, stone bank, petrol refinery, electric spark vulnerability, open-air steel closed gas tank ii with explosive risk, electric spark vulnerability, and mine-protected building iii. 2
Categorization of mine-proof technologies: external, internal, mine-protected electromagnetic pulses. 3 the external mine-proofing device of the mine-protecting device is directly hit: a flasher, pull-down line, ground-laying device; the range of protection of the flasher is determined by the roller method, the radius of the roller is determined by the type of mine-protective building, i. E. 30m, category ii 45m, category iii 60m; the line dedicated to direct-attacking is not suitable to be less than 3m along the entrance to the building or the side of the sidewalk; the impact of an independent flash rod should not be more than 10; and the impact-blocking of each line attached to the bolt should not be greater than 10. Internal mine-protective devices: shielding conductors, electrical level connectors, electric surge protectors spds, mine avoidance devices. For electrical transformation equipment, mine avoidance devices are often used as a device to prevent thunderwave intrusion. When normal, the shield remains insulated from the ground; when a thunderstorm arrives, the shield is pierced and the lightning is brought to the ground; when the shock wave passes, the shield automatically recovers the insulation. Zinc oxide
17. Mine avoidance devices are widely used. Ii. Seven measures 1 for electrostatic protection and environmental hazard level control, including: replacement of flammable media, reduction of concentrations of explosive gases, vapour mixtures and reduction of oxidizer content. Process control: is an important method of eliminating electrostatic hazards, including the selection of materials, limiting the speed of movement of materials, and increasing the process of electrostatic dispersion. 3. Electrostatic sites: fundamental measures. 4. Wetting 5, anti-static additives 6, electrostatic neutrals 7, prevention of human electrostatic hazards, strengthening of electrostatic safe management. Electrical installations are safe, the distribution station is safe, and the location of the distribution station is free of the flammable and explosive environment. 2. Building structures: fire-resistant buildings; door opening and setting: electrical distribution units should be open on both sides, and at least two doors should be available for high- and low-composed over 7 m and over 10 m. 3. Spacing, screening and isolation: fuel volume of indoor filling equipment 60k
Persons below 18,g are allowed to be installed at intervals with partitions on both sides, 60,600 kg at intervals with blast barriers and above 600 kg at separate intervals. Channels: two exits at 6 m for high-assembly devices; additional exports at 15 m for low-assembly devices. 7 signs: "stop, pressurized, dangerous". Ii. Installation of main transformer 1 and electrical transformer 1 transformer: fireproof doors; oil-impregnated transformers installed in residential buildings with a capacity not exceeding 400 kv a; 10 kv transformer shell doors not less than 1 m and walls not less than 8 m (not less than 12 m when installed with an operational switch); natural ventilated transformer rooms should be above the outer surface of 11m; outdoor transformers should not exceed 315 kv a and above 315 kv a should be installed on stage; and secondary leads
19. Insulation steering lines shall be used; the base of the transformer on the column shall not be less than 25 m above the ground height, and the naked conductor shall not be less than 35 m below the ground altitude; the transformer table shall generally not be less than 05m below the height of the fence shall not be less than 1. 7 m below, the shell shall not be less than 1 m below the fence and the operational surface shall not be less than 2 m below the fence. (b) operation of 2 transformers: the pressure side deviation of the operational transformer shall not exceed ±5 of the rated value, the maximum imbalance current of the low pressure shall not exceed 25 of the rated current, and the temperature of the upper layer shall not normally exceed 85; the colour of the suction inside the respirator shall be light blue; the relative humidity of the air at the installation of the dry transformer shall not exceed 70%. 2. High pressure switches: high pressure breakers, high pressure isolation switches and high pressure load switches: the most important and complex switches in high pressure switches. There's a strong anti-arc device that can connect and break load currents under normal conditions, and a relay protection device
20. Cut-off of charged and short-circuit currents in case of failure. High-pressure breakers must be used in combination with high-pressure isolation switches or isolation plugs, with circuit breakers connecting and cutting out electrical currents, and separation switches or plugs cutting off power sources. Therefore, the circuit must be cut by pulling the breaker and then pulling the quarantine switch; the circuit must be connected by closing the isolation switch and then closing the breaker. Mechanical or electromagnetic locking devices are often installed in 10kv systems. 2 high pressure isolation switch: high pressure isolation switch abbreviated switch. The separation switch does not have a dedicated anti-arc mechanism, which cannot be used to connect and break load currents, let alone cut short circuit currents. The separation switch is used primarily to isolate the power supply to ensure the safety of the overhaul and downing operations; copper and aluminium conductors are required to be connected with a copper aluminium transition; and operating high pressure isolation switch connections do not exceed 75 degrees of temperature and institutions should be flexible. 3 high pressure load switches: there are relatively simple arc suppression devices to connect and break load currents; they must be used in conjunction with high pressure smelting machines, which cut short circuit currents; no combustible material shall be present in front. Iii. Electronic transfer box 1, electronic arrangement
