Technical measures to prevent electric shock

I. Direct contact electrical protection measures For direct contact with electricity, the protective measures taken are as follows:

1. Insulation. That is, insulation is used to prevent access to the charged body. It should be noted that the use of similar insulation such as paint and lacquer to prevent electric shock is not enough.

2, screen protection. Use a barrier or fence to prevent access to live parts. In addition to preventing unintentional access to the body, the barrier or fence can at least make people aware of the dangers of crossing the barrier or fence to avoid touching the charged body.

3. Obstacles. That is, an obstacle is set to prevent inadvertent contact with the charged body, or close to the charged body, but it is not prevented from intentionally bypassing the obstacle to reach the charged body.

4. Interval. That is, the spacing is maintained to prevent unintentional access to the charged body. Any electrically accessible body that is easily accessible should be kept out of the reach of the arm. If the tool is used up normally, the interval should be increased.

5. Safety signs. It is an important measure to ensure safe production and prevent electric shock.

6. Leakage protection device. Leakage protection is also called residual current protection or ground fault current protection. Leakage protection is only used as an additional protection and should not be used alone. The operating current is less than or equal to 30 mA.

7, safe voltage. That is, according to the characteristics of the site, the corresponding level of safety voltage is adopted.

Second, the contact electrical protection measures For the contact electricity, the following protective measures can be taken:

1. Automatically disconnect the power supply. This measure is based on the operating mode and safety requirements of the low-voltage distribution network, using appropriate automation components and connection methods to automatically disconnect the power supply within a specified time period in the event of a fault, preventing the risk of contact voltage.

2. Strengthen insulation. This measure is to use electrical equipment with double insulation or reinforced insulation, or a combination of electrical equipment with common insulation to prevent dangerous ground voltage in the accessible part after the working insulation is damaged.

3. Non-conductive environment. This measure is to prevent the human body from touching two points of different potentials at the same time when the working insulation is damaged. This protection condition is met when the wall and floor of the environment are both insulated and the distance between two points where different potentials may occur is more than 2 m.

4. Equipotential environment. This measure connects all bare conductors (including bare conductors outside the equipment) that are easily accessible at the same time to prevent dangerous contact voltages.

5. Electrical isolation. This measure is to use an isolation transformer or a generator with equivalent isolation to provide electrical isolation to prevent electric shock when the exposed conductor fails. The voltage of the isolated circuit should not exceed 500V; its live parts cannot be connected to other electrical circuits to ensure isolation requirements.