12 kinds of weak security security tips

1. Why must the lighting switch be connected to the fire?

If the light switch is installed on the zero line, although the light does not turn on when the light is turned off, the phase line of the light head is still turned on, and people think that the light is off, they will erroneously think that it is in a power-off state. In fact, the ground voltage at each point on the luminaire is still a dangerous voltage of 220 volts. If people touch these actually live parts when the lamp is off, it will cause electric shock. Therefore, the switches of various lighting switches or single-phase small-capacity electrical equipment can only be secured if they are connected in series to the fire line.

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

In general, single-phase electrical equipment, especially portable electrical equipment, should use three-pin plugs and matching three-hole sockets. There is a special protection zero (ground) jack on the three-hole socket. When the zero protection is used, someone often directly connects this hole in the bottom of the socket with the neutral line in the input socket. This is Extremely dangerous. Because if the zero line of the power supply is disconnected, or if the fire (phase) line and neutral line of the power supply are reversed, the metal parts such as the housing will also carry the same voltage as the power supply, which will result in electric shock.

Therefore, the dedicated ground jack should be connected to the dedicated protective grounding wire when wiring. When using zero protection, the zero line should be specifically drawn from the power supply, instead of using the zero line introduced into the nearest outlet.

3, Why is it forbidden to directly bury the plastic insulated wire in the wall?

(1) When plastic insulated wire is used for a long time, the plastic will be aged and cracked, and the insulation level will be greatly reduced. When the circuit is overloaded or short-circuited for a short time, it is easier to accelerate the insulation damage.

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

(3) Directly buried plastic insulated wire is not conducive to line inspection and maintenance.

4. Why use a leakage protector?

Leakage protector, also known as leakage protection switch, is a new type of electrical safety device, its main purpose is:

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

(2) Prevent single-phase electric shock in the process of electricity use.

(3) The single-phase earth fault in the operation of electrical equipment is cut off in time to prevent electrical fire accidents caused by electrical leakage.

(4) With the improvement of people's living standards and the continuous increase of household appliances, in the course of electricity use, due to the defects of electrical equipment itself, improper use, and unsafe technical measures, personal electric shocks and fire accidents are caused to people’s lives. And the property has brought undue losses, and the emergence of leakage protection devices, to prevent the occurrence of various types of accidents, cut off power in a timely manner, protect equipment and personal safety, provide a reliable and effective technical means.

5. What are the main causes of electric shock?

Statistics show that the main causes of electrocution accidents are the following:

(1) Lack of electrical safety knowledge, flying a kite near high-voltage lines, climbing high-voltage poles and gnawing the bird's nest; after low-voltage overhead lines are disconnected, they will continue to use their hands to pick up the fire line; the night-time electrified wiring hand touches live bodies; Plastic cover cutter.

(2) Violation of operating procedures, electrified connection to lines or electrical equipment without taking necessary safety measures; touching damaged equipment or wires; mischarging charged equipment; lighting fixtures with electricity, repairing power tools with electricity, and electrifying mobile electrical equipment; Wet hand bulbs and so on.

(3) The equipment is unqualified, the safety distance is not enough; the grounding resistance of the second-wire and ground system is too large; the grounding wire is unqualified or the grounding wire is disconnected; the insulation destruction wire ** is outside.

(4) The equipment is in disrepair, the wind blows the circuit or the pole is not repaired in time; the bakelite damage of the plastic cover switch is not changed in time; the motor wire is broken and the shell is charged for a long time; the porcelain bottle is destroyed and the phase wire and the pull wire are shorted. The device housing is charged.

(5) For other accidental reasons, the nighttime walking touches live conductors that have fallen off the ground.

6. What rescue measures should be taken when an electric shock occurs?

In the event of an electric shock, while ensuring the safety of the ambulance itself, it is necessary to first try to get the electric shocker out of the power quickly, and then perform the following repair work.

(1) Untighten the tight clothing that prevents the electric shocker from breathing.

(2) Check the mouth of the person who has received the electric shock and clean up the mucus in the mouth. If there is any denture, remove it.

(3) Immediately on-site rescue operations, such as stopping breathing, using mouth-to-mouth artificial respiration rescue, if the heart stops beating or irregular tremors, artificial chest compression can be rescued. It must not be interrupted without reason.

If a second person is present in addition to the rescuer at the scene, the following work should also be carried out immediately:

1) Provide first aid tools and equipment.

2) Dismiss the casual staff at the scene.

3) Keep enough lighting on site and maintain air circulation.

4) Report to the leader and ask the doctor to come to the rescue.

Experimental studies and statistics show that 90% of people can be saved if treatment is started from 1 minute after electrocution, and only 10% of rescue opportunities are available if they are rescued from 6 minutes after electrocution, and rescue is started 12 minutes after electrocution. The possibility of survival is minimal. Therefore, when someone is found to have an electric shock, they should fight against the seconds and use all possible methods.

7. What are the measures for household safe electricity use?

With the popularization and application of household appliances, it is very important to correctly grasp the knowledge of safe use of electricity and ensure the safety of electricity.

(1) Do not buy "three no" fake and shoddy household products.

(2) When using home appliances, there should be a complete and reliable power cord plug. Home appliances for metal enclosures must be grounded.

(3) Switches and fuses cannot be installed on the ground and neutral wires. It is forbidden to connect the grounding cable to tap water and gas pipelines.

(4) Do not touch the live device with wet hands, and do not wipe the live device with a damp cloth.

(5) Do not pull the cable and do not move the charged device.

(6) When checking and repairing home appliances, the power must be turned off.

(7) When the power cord of the household appliance is damaged, immediately replace it or wrap it with an insulating cloth.

(8) When there is a fire in a household appliance or a wire, disconnect the power and then extinguish the fire.

8. How to prevent burning of household appliances?

The rated voltage of commonly used household appliances is 220 volts, and the normal supply voltage is around 220 volts. When the power supply voltage is instantaneously increased due to a lightning strike or other natural disaster in the power supply line, the zero-phase fault occurs when the three-phase load is unbalanced, or the voltage rises due to phase voltage rise caused by human error wiring. As a result, the current increases causing the household appliance to burn due to overheating. To prevent the burning of household appliances, it is necessary to start from the following aspects: First, when the power equipment is not used, it should be disconnected as much as possible; second, transform the old and unrepaired receiver line; third, install an over-voltage protection leakage switch.

9. How to match the fuses for households?

Household fuses should be selected based on the size of the capacity used. If a meter with a capacity of 5 A is used, the fuse shall be greater than 6 A and less than 10 A; if a meter with a capacity of 10 A is used, the fuse shall be greater than 12 A and less than 20 A. That is, the selected fuse shall be 1.2 2 times. The selected fuse should be one that complies with the regulations. It cannot use multiple fuses with small-capacity fuses. It cannot use copper wires instead of fuses.

10. What are the basic requirements for a leakage protector?

Technically it should meet the following requirements:

(1) The sensitivity of the electric shock protection should be correct and reasonable. The general starting current should be in the range of 15~30 mA.

(2) The operating time of the electric shock protection should not exceed 0.1 second under normal circumstances.

(3) The protector shall be equipped with necessary monitoring equipment to prevent loss of protection when the operating state changes. For a voltage type electric shock protector, a neutral grounding device shall be installed.

11. How to prevent electrical fire accidents? What happens after a fire?

First of all, when installing electrical equipment, quality must be ensured and all requirements for safe fire protection should be met. Use qualified electrical equipment. Damaged switches, lamp caps, and broken wires must not be used. Wire connections should be securely connected and secured with insulating tape. Wiring the wiring pile heads and terminals must be tightened to prevent poor contact due to loose wiring. After the electrician installs the equipment, it does not mean that it can be used once and for all. If the user finds that the lamp and the socket are loosely connected (especially the mobile electrical plug is easy to loose), the contact is bad or there is overheating, and the electrician must be dealt with in time. .

Second, don't place oil, cotton, sawdust, wood, and other contaminated items near the low-voltage lines, switches, sockets, and fuses.

Before the electric fire, there is a kind of precursor. Special attention should be paid to the fact that the electric wire will scorch the insulation sheath first because of overheating, and emit a bad smell that burns rubber and burns plastic. Therefore, when you smell this odor, you should first think that it may be caused by electrical reasons. If you do not find any other reason, you should immediately switch off the power until you find out the reason and handle it properly before switching on.

In case of a fire, whether it is caused by electricity or not, first of all, we must think of ways to quickly cut off the power within the scope of the fire. Because if the fire is caused by electricity, the power supply is cut off and the fire source is cut off. If the fire is not caused by electricity, the insulation of the wire will be burned. If the power is not cut off, the burned wire will cause damage. A short circuit to the touch causes a wider range of wires to catch fire. In the event of an electrical fire, cover soil, cover sand or fire extinguishers should be used, but foam fire extinguishers must not be used, so the extinguishing agent is electrically conductive.

12, home safety electricity knowledge

(1) Each household must have some necessary electrical appliances such as electroscopes, screwdrivers, and glue clamps, as well as various types of fuses and fuses suitable for the use of household appliances.

(2) The total insurance must be installed before every household meter, and the total knife gate and leakage protection switch should be installed after the meter.

(3) It is forbidden to use copper and iron wire instead of fuse in any case. The size of the fuse must match the capacity used. When replacing the fuse, remove the porcelain cover and replace it. Do not lap the fuse directly in the porcelain case. Do not replace the fuse in the live condition (without opening the knife).

(4) After the fuse or the leakage switch is blown, it is necessary to find out the reason to close the switching power supply again. Under no circumstances shall the conductors be short-circuited or pressed against the leakage switch tripping mechanism for forced transmission.

(5) When purchasing household appliances, it is necessary to carefully check whether the technical parameters (such as frequency, voltage, etc.) of the product specification are in line with the local electricity requirements. It is necessary to know how much power is consumed and whether the existing power supply capability of the family satisfies the requirements, especially whether the wiring capacity, plugs, sockets, fuses, and meters meet the requirements.

(6) When the household power distribution equipment cannot meet the capacity requirements of the household appliances, it should be replaced and modified. It is forbidden to make use of it. Otherwise, overloaded operation can damage electrical equipment and may cause electrical fire.

(7) The purchase of household appliances should also understand its insulation properties: whether it is general insulation, reinforced insulation or double insulation. If it is grounded for leakage protection, the grounding line is essential. Even for reinforced or double-insulated electrical equipment, it is beneficial to provide protective grounding or zero protection.