Ten weak electric common sense electrical practitioners must know

1. Why should the lighting switch be connected to the fire line?

If the lighting switch is installed on the zero line, although the light is not turned off when the light is off, the phase line of the light head is still turned on, and people think that the light is not bright, it is mistakenly considered to be 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 charged parts when the light is off, it will cause an 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 on the fire line.
 

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

Generally, single-phase electrical equipment, especially mobile electrical equipment, should use a three-pin plug and a three-hole socket. There is a special protective zero (ground) jack on the three-hole socket. When using zero-connection protection, it is often only directly connected to the hole terminal in the socket bottom and the zero wire that is introduced into the socket. Extremely dangerous. Because if the neutral line of the power supply is disconnected, or the fire (phase) line and the neutral line of the power supply are reversed, the metal part such as the outer casing will also carry the same voltage as the power supply, which will result in electric shock.

Therefore, the dedicated grounding jack for wiring should be connected to a dedicated protective grounding wire. When using zero-connection protection, the zero line should be specifically drawn from the power supply terminal, and should not be used near the neutral line of the socket.
 

3. Why is it not strictly buried in the wall?

(1) After long-term use of plastic insulated wires, the plastic will age and crack, and the insulation level will be greatly reduced. When the line is short-time overload or short-circuit, it is easier to accelerate the insulation damage.

(2) Once the wall is wet, it will cause large-area leakage and endanger personal safety.

(3) The plastic insulated wire is directly buried in the dark, which is not conducive to line maintenance and maintenance.

4. Why use a leakage protector?

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

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

(2) Prevent single-phase electric shock accidents during power consumption.

(3) Cut off the single-phase ground 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, due to defects in electrical equipment, improper use and unfavorable safety technical measures, personal electric shock and fire accidents give life to the people. And the property has brought undue losses, and the appearance of leakage protectors provides reliable and effective technical means for preventing the occurrence of various accidents, cutting off the power supply in time, protecting equipment and personal safety.

5. What is the main reason for an electric shock accident?

Statistics show that the main causes of electric shock accidents are as follows:

(1) Lack of electrical safety knowledge, fly a kite near the high-voltage line, climb the high-voltage pole and smash the bird's nest; after the low-voltage overhead line is broken, do not stop using the hand to pick up the fire line; the night-time electrified wiring hand touches the charged body; Rubber cover knife brake.

(2) Violation of the operating procedures, connecting the line or electrical equipment without taking the necessary safety measures; touching the damaged equipment or wires; accidentally charging the live equipment; charging the lighting fixtures; charging the electric tools; charging the mobile electrical equipment; Wet hand twisting the bulb and so on.

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

(4) The equipment is in disrepair, the wind blown line or the scraping pole is not repaired in time; the bakelite damage of the rubber cover knife gate is not changed in time; the motor wire is damaged, so that the outer casing is charged for a long time; the porcelain bottle is broken, so that the phase line and the pull wire are short-circuited. The device housing is live.

(5) For other accidental reasons, walking at night touches the live conductor that has fallen off the ground.

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

In the event of an electric shock, while ensuring the safety of the rescuer, you must first try to get the electric shocker out of the power supply quickly, and then carry out the following repair work.

(1) Untie the tight clothes that hinder the breathing of the electric shock.

(2) Check the mouth of the electric shocker and clean the mucus in the mouth. If there is a denture, remove it.

(3) Immediately carry out the rescue on the spot, such as breathing stop, using mouth-to-mouth artificial respiration to rescue, if the heart stops beating or irregular vibration, artificial chest extrusion method can be used to rescue. It must not be interrupted without cause.

If there is a second person present in addition to the rescuer on site, you should immediately do the following:

(1) Provide tools and equipment for first aid.

(2) Dismiss the on-site staff.

(3) Keep enough lighting on the site and keep the air flowing.

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

Experimental studies and statistics show that if treatment is started 1 minute after the electric shock, 90% can be saved; if rescue is started 6 minutes after the electric shock, only 10% of the rescue opportunities will be available; and 12 minutes after the electric shock, the rescue will be started. The possibility of saving is extremely small. Therefore, when someone is found to have an electric shock, they should race against time and adopt all possible methods.
 

7. What are the measures for household safety?

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

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

(2) When using home appliances, there should be a complete and reliable power cord plug. Grounding protection is required for household appliances in metal enclosures.

(3) Switches and fuses cannot be installed on the ground and neutral lines. Do not connect the ground wire to the tap water or gas pipe.

(4) Do not touch live equipment with wet hands. Do not wipe the live equipment with a damp cloth.

(5) Do not pull the wires randomly, do not move the live equipment.

(6) When inspecting and repairing household appliances, the power must be disconnected first.

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

(8) When a household appliance or electric wire is involved in a fire, the power should be disconnected before the fire is extinguished.

8. How to prevent burning of household appliances?

The commonly used household appliances are rated at 220 volts and the normal supply voltage is around 220 volts. When the power supply line is instantaneously increased due to natural disasters such as lightning strikes, the three-phase load unbalanced household line is in disrepair, the voltage is increased due to the phase voltage rise caused by human error wiring, etc. This will increase the current and cause the household appliance to burn out due to overheating. To prevent burning of household appliances, we must start from the following aspects: First, the electrical equipment should be disconnected from the power supply when not in use; second, the old and damaged repair line should be modified; third, the over-voltage protection leakage switch should be installed.

9. How to choose the fuses for households?

The fuses used by households should be selected according to the size of the electricity used. If using a meter with a capacity of 5 amps, the fuse should be greater than 6 amps and less than 10 amps; if using a meter with a capacity of 10 amps, the fuse should be greater than 12 amps and less than 20 amps, that is, the fuse used should be 1.2~ of the meter capacity. 2 times. The fuses to be used should be one that meets the requirements, and cannot be used in combination with a small-capacity fuse, and the copper wire cannot be used instead of the fuse.

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

Technically, the following requirements should be met:

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

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

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