1. There are two basic forms of lightning overcharge:
One: direct lightning - also called direct lightning
And the second one: thunderborne -- also known as sensory thunder
2. The function of a flasher:
The flasher is a metal body used to receive direct lightning, and it must be connected to the offline through the ground。
3. The function of a lightning rod:
The role of a lightning rod is in fact to induce a mine, which is used to protect against direct fire。
4. Type of use and function of mine avoidance devices:
The commonly used mine avoidance devices are valves, vents (pipes), zinc oxide, etc。
Mine avoidance devices are used to protect against the insulation of protected objects by way of intrusion into the transformer room or other building along the thunderstorm peroxide. Zinc oxide shield is now commonly used outside the distribution room, and valves are commonly used in the room。
5. Mine-protective measures commonly used in plant conversion rooms:
Direct impact mines are protected against thunderwave intrusion by means of a lightning rod (or cord, belt, grid)。
6. Concept of safe current:
Safe currents refer to the largest withdrawals of humans from electricity after exposure. We have established a safe current of 30 mhz. Safe currents are associated with such factors as the timing of electrical exposure, the nature of the current, the current path and weight and health status。
7. Concept of safe voltage:
Safe voltage means the voltage that does not cause death or disability directly. We have set a safe, very low voltage at 36 volts。
8. Concept of place:
Electrical land (or land) means an area with zero electrical level; this area generally refers to an area about 20 metres away from the site's failure point。
9. Exposure to voltage, cross-step voltage:
Exposure to voltage is the earth-to-ground voltage that is present in human contact with the exposed conductive parts of the equipment where the ground failure occurs; the cross-step voltage is the level difference between the feet when the person moves near the ground failure point。
10. The concept of place of work, place of protection:
The site is called to ensure that the electrical system and equipment meet the requirements of normal work。
The area used to secure personal security against inter-mission access to electricity is called the protection site。
For example, the neutral location of transformers, the location of flashers and the location of mine avoidance devices are work sites. The second-side end of the sensor, the shell of the device, is protected。
11. Several forms of protection are currently used:
Tn systems, tt systems, it systems。
It is divided into three types of protection in the tn system: tn-c, tn-s and tn-c-s。
12. Level connection: the level connection can be divided into total level connection, auxiliary level connection。
The purpose of this practice is to connect directly to the pe line the electrically conductive metal objects that a person may be exposed to. International and national regulations stipulate that power lines should be connected to the main level of power supply, and that all metal components and pipes near the power lines should be connected to the pe line. Additional power level connections, such as auxiliary connections, must also be made at specially humid, electrically hazardous sites (e. G. Bathrooms), where all metal components, pipes and pe lines are reconnected。
13. The first thing to do when electrocution is detected is to find a way to remove the electrocutor quickly from the power supply and then perform other forms of first aid。
