Matters needing attention in safe use of electricity

1. Why does the lighting switch have to be connected to the live wire?

If the lighting switch is installed on the zero line, although the light is not on when it is turned off, the phase line of the lamp holder is still on, and people will think that the light is not on and will mistakenly think that it is in a power-off state. In fact, the ground voltage of each point on the lamp is still a dangerous voltage of 220 volts. If people touch these actually charged parts when turning off the lights, it will cause an electric shock accident. Therefore, all kinds of lighting switches or switches of single-phase small-capacity electrical equipment can only be connected in series on the live line to ensure safety.

2. How to correctly install the single-phase three hole socket? Why?

Usually, single-phase electrical equipment, especially mobile electrical equipment, should use three-core plug and its supporting three hole socket. There is a special protective zero (grounding) jack in three hole socket. When using zero protection, it is very dangerous for someone to directly connect the wiring pile head of this hole with the zero line that only leads into the socket at the bottom of the socket. Because in case the zero line of the power supply is disconnected, or the fire (phase) line and the zero line of the power supply are connected reversely, its shell and other metal parts will also bring the same voltage as the power supply, resulting in electric shock.

Therefore, when wiring, the special grounding jack should be connected with the special protective grounding wire. When zero protection is adopted, the zero line should be led out from the power supply side, and the zero line introduced into the socket should not be used nearby.

3. Why is it forbidden to bury plastic insulated wires directly in the wall?

(1) Plastic insulated conductor will age and crack after long-term use, and the insulation level will be greatly reduced. When the line is overloaded or short-circuited, it is easier to accelerate the insulation damage.

(2) Once the wall is damp, it will cause a large area of leakage and endanger personal safety.

(3) Plastic insulated wires are directly buried, which is not conducive to line maintenance and repair.

4. Why should I use a leakage protector?

Leakage protector, also known as leakage protection switch, is a new type of electrical safety device. Its main purposes are:

(1) Prevent electric shock accidents caused by leakage of electrical equipment and circuits.

(2) To prevent single-phase electric shock accidents in the process of electricity utilization.

(3) Cut off the single-phase grounding fault in the operation of electrical equipment in time to prevent electrical fire accidents caused by leakage.

(4) With the improvement of people's living standards, the number of household appliances is increasing. In the process of using electricity, personal electric shock and fire accidents caused by defects in electrical equipment, improper use and unfavorable safety technical measures have brought undue losses to people's lives and property. The appearance of leakage protector provides a reliable and effective technical means for preventing all kinds of accidents, cutting off power supply in time and protecting equipment and personal safety.

1) Don't buy fake and shoddy "three noes" household products.

(2) When using household appliances, there should be a complete and reliable power cord plug. Household appliances with metal shell should be protected by grounding.

(3) Switches and fuses cannot be installed on the ground wire and zero wire. It is forbidden to connect the ground wire to the tap water and gas pipeline.

(4) Don't touch the live equipment with wet hands, and don't wipe the live equipment with wet cloth.

(5) Don't connect wires privately, and don't move live equipment casually.

(6) When repairing household appliances, you must first disconnect the power supply.

(7) When the power cord of household appliances is damaged, it should be replaced immediately or wrapped with insulating cloth.

(8) When household appliances or wires catch fire, disconnect the power supply first, and then put out the fire.

First of all, when installing electrical equipment, we must ensure the quality and meet the requirements of safety and fire prevention. Qualified electrical equipment should be used. Do not use broken switches, lamp holders and broken wires. Wire connectors shall be firmly connected according to the specified connection method and wrapped with insulating tape. Tighten the connection of the connection pile head and terminal to prevent poor contact caused by loose connection. After the electrician installs the equipment, it does not mean that it can be done once and for all. In the process of use, if users find that the wiring of lamp holder and socket is loose (especially the wiring of plug of mobile appliances is easy to be loose), the contact is poor or there is overheating, they should find an electrician to deal with it in time.

Secondly, do not place oil, cotton, sawdust, wood and other easily dyed items near low-voltage lines and switches, sockets and fuses.

Before an electrical fire, we should pay special attention to a precursor, that is, the wires will first burn the insulation sheath due to overheating, giving off an unpleasant smell of burnt rubber and burnt plastic. Therefore, when you smell this smell, you should first think that it may be caused by electrical reasons. If no other reason can be found, turn off the power immediately until the reason is found out and properly handled.

In the event of a fire, whether it is caused by electricity or not, we must first find ways to cut off the power supply in the fire area quickly. Because, if the fire is caused by electricity, cutting off the power supply will also cut off the fire source; If the fire is not caused by electricity, it will also burn out the insulation of the wire. If the power supply is not cut off, the burnt wire will cause a short circuit and cause a wider range of wires to catch fire. After an electrical fire, cover soil, sand or fire extinguisher should be used, but foam extinguisher should not be used, so this fire extinguishing agent is conductive.

(1), every family should have some necessary electrical appliances, such as pencil, screwdriver, rubber pliers, etc. , but also must have various specifications of fuses and fuses suitable for the right to use household appliances.

(2), every household meter must be equipped with master insurance, and the meter should be equipped with master breaker and leakage protection switch.

(3) In any case, it is forbidden to use copper wire and iron wire instead of fuse. The size of the fuse must match the capacitance. When replacing the fuse, remove the porcelain box cover and replace it. It is not allowed to overlap the fuse directly in the porcelain box, and it is not allowed to replace the fuse with electricity (without opening the circuit breaker).

(4), fuse blowing or leakage switch action, must find out the reason to turn off the switching power supply. Under any circumstances, it is not allowed to use the short-circuit insurance of wires or the tripping mechanism of forced leakage switch to send electricity.

(5) When purchasing household appliances, carefully check the technical parameters (such as frequency, voltage, etc.). ) meet the local power consumption requirements. It is necessary to know how much electricity is used and whether the existing power supply capacity of the family meets the requirements, especially whether the wiring capacity, plugs, sockets, fuses and meters meet the requirements.

(6), when the household power distribution equipment can't meet the requirements of household appliances capacity, should be replaced, it is forbidden to make do with it. Otherwise, overload operation will damage electrical equipment and may also cause electrical fire.

(7) When buying household appliances, you should also know their insulation performance: general insulation, reinforced insulation or double insulation. If grounding is used for leakage protection, grounding wire is essential. Even for electrical equipment with reinforced insulation or double insulation, it is beneficial to do protective grounding or protective grounding.

(8) Household appliances with motors (such as electric fans, etc.). ), you should also know the heat resistance level and whether it runs continuously for a long time. Pay attention to the heat dissipation of household appliances.

(9) Before installing household appliances, you should check the requirements of the product manual for the installation environment, and pay special attention not to install household appliances in an environment with damp heat, dust or flammable, explosive and corrosive gases as much as possible.

(10), when wiring indoors, the phase line and the zero line should be clearly marked and consistent with the wiring of household appliances, and they should not be staggered.

(1 1), the connection between household appliances and power supply must use switches or plugs, and it is forbidden to directly insert wires into socket holes.

(12), all household appliances requiring protective grounding or safe zero connection should adopt three-pin plugs and three-pin sockets, and two-pin plugs and two-pin sockets are not allowed to be used instead, resulting in neutral grounding (or zero connection) wires.

(13), it is better to have no connector in the middle of home wiring. If there must be a joint, it should be firmly contacted, wrapped with insulating tape, or a porcelain junction box. Standard uses medical tape instead of electrical tape to wrap joints.

(14), wires and switches, circuit breakers, fuse boxes, lamp holders, etc. The connection is firm and reliable, and the contact is good. The multi-rubber flexible copper wire connector should be twisted first, and then placed under the connector screw gasket to prevent the thin strands from spreading and contacting another connector and causing short circuit.

(15), household wiring shall not be directly laid on flammable building materials, and porcelain beads or clamps must be used if wiring is needed on wood; Porcelain sleeves must be used to penetrate the board. Flammable plastics and other flammable materials shall not be used as decorative materials.

(16), the grounding or neutral line is normally not charged, but in case of leakage after disconnection, the shell of the right electrical appliance will be charged; In the case of short circuit, the grounding wire also passes a large current. For the sake of safety, the specification of the grounding (neutral) wire shall not be lower than that of the phase wire, and switches, fuses or connectors shall not be installed on it.

(17), the grounding wire should not be connected to the tap water pipe (because the tap water pipe joint is now sealed with insulating tape and has no grounding function); Do not connect it to the gas pipe (in case of gas explosion caused by electric spark); Don't connect it to the ground wire of the telephone line (in case of strong current and weak current); Nor shall it be connected to the down lead of lightning rod (to prevent lightning strike).

(18), all switches, knives and fuse boxes must be covered. Bakelite cover plate is aging and incomplete and must be replaced. Dirty and wet people must be wiped clean before use after power failure.

(19), the power cord should not be dragged on the ground to prevent the power cord from tripping and damaging the insulation.

(20) Before household appliances are tried out, all switches and buttons should be placed in the original stop position according to the requirements of the manual, and then the start-stop operation sequence required by the manual should be carried out. If there are moving parts, such as a head-shaking fan, sufficient motion space should be considered in advance.

(2 1), when household appliances are found to be sparking, smoking or burning after being electrified, stop immediately and cut off the power supply for inspection.

(22) When moving household appliances, be sure to cut off the power supply to prevent electric shock.

(23), around the heating appliance must be far away from flammable materials. Electric stove, heating stove, electric iron and other heating appliances should not be placed directly on the board to avoid fire.

(24), it is forbidden to touch the live switch with wet hands; It is forbidden to plug the power supply with wet hands; When unplugging the power plug, fingers must not touch the metal part of the contact; Never replace electrical components or light bulbs with wet hands.

(25) Used in household appliances (such as hair dryer, electric soldering iron, etc.). ) It is often used in your hands, and it is forbidden to wrap wires around your hands.

(26) Household appliances in contact with human body, such as electric blankets, electric oil caps, electric shoes, etc. Before use, it should be electrified for testing and inspection, and it can only touch the human body after there is no leakage.

(27) It is forbidden to move household appliances by dragging wires; It is forbidden to pull the plug by dragging the wire.

(28), when using household appliances, plug in the neutral end of the socket first, and finally close the knife switch or plug in the live end socket; On the contrary, when stopping the use of household appliances, first pull the circuit breaker on the live side or pull out the socket on the live side, and then pull out the socket on the dead side (if necessary).

(29) When it is necessary to cut off the power supply wire in an emergency, insulated electrician tongs or insulated handle cutters must be used.

(30), rescue electric shock personnel, first of all, to disconnect the power supply or use wood, insulating rod pick open the power cord, don't directly drag electric shock personnel by hand, so as to avoid serial electric shock.

(3 1), household appliances, except refrigerators, should be turned off at will, especially electrical appliances, to prevent fires caused by long-term heating.

(32), bed switch is strictly prohibited. Except for electric blankets, don't lead charged electrical equipment to the bed, close to the sleeping human body. Even if an electric blanket is used, it is recommended to turn off the power supply after heating to ensure safety if it is not necessary to keep warm all night.

(33), household appliances burning, smoking, fire, must immediately disconnect the power supply, shall not be sprayed with water or foam extinguisher.

(34), indoor wiring and electrical equipment insulation should be checked regularly, found that the damage should be promptly wrapped with electrical tape.

(35) The insulation resistance of household appliances that have not been used or reused for a long time before the rainy season should not be lower than1mΩ when measured with a 500V shaking table, which can be considered as good insulation and can be used normally. If there is no shaking table, at least use a test pen to regularly check whether there is any leakage.

(36) For household appliances that are often used, keep them dry and clean. Do not wipe the surface of household appliances with corrosive or conductive liquids such as gasoline, alcohol, soapy water and decontamination powder.

(37) After household appliances are damaged, please ask professionals or send them to a repair shop for repair; Non-professionals are strictly forbidden to open the shell of household appliances under live conditions.

(1) Keep away from high-voltage charged bodies (outdoors, beside high-voltage lines and transformers) and avoid contact with low-voltage charged bodies. ?

(2) Insert or pull out the plug without using the wet manual switch. ?

(3) Installation and maintenance of electrical appliances should wear insulating shoes, stand on the insulator and cut off the power supply. ?

(4) It is forbidden to use copper wire instead of fuse and rubber instead of electrical insulation tape. ?

(5) Install an electric shock protector in the circuit and check its sensitivity regularly. ?

(6) Do not use the radio, video recorder and TV set in thunderstorm weather, and unplug the power plug and antenna plug of the TV set. Don't use the phone for the time being If you must use it, you can use the hands-free function. ?

(7) It is forbidden to connect wires without permission, and students are forbidden to use electric stoves, "quick heating" and other electrical appliances in the dormitory. ?

(8) Don't fly kites or play ball under telephone poles and wires.