There are 9 points of Tips of Electric Power for reference.
1. When a fire occurs in electrical equipment, the equipment that can be charged to extinguish the fire includes 1211, carbon dioxide, carbon tetrachloride, and dry powder.
2. The maximum safe voltage is 42 volts (12 volts in humid places).
3. Safety current through the body: AC 10 mA, DC 50 mA.
4. The insulation resistance of electrical equipment casing (metal) and external lines should not be less than 0.5 megohms.
5. The operating current of the leakage protector should not be greater than 10 mA.
6. The lighting switch must be connected in series on the phase line. It is strictly forbidden to connect the zero line in series, otherwise there is a danger of electric shock when replacing the lamp.
7. The protection "grounding" and "zeroing" of equipment in the same power supply system must be unified, that is, the protection of the metal shell of each electrical equipment connected to the same transformer power supply line can only be unified in one protection method. Mixing of the two protection methods is not allowed.
8. The "neutral line" of the low-voltage distribution line must be grounded repeatedly. In the distribution lines with long low-voltage distribution lines or concentrated power loads, repeated grounding protection should be performed on the "neutral line" at intervals to prevent the three-phase load from being disconnected from the neutral line and the unbalanced three-phase load of the neutral line. The displacement of the midpoint of the potential voltage increases or decreases the phase voltage and burns the 220-volt electrical equipment.
9. The insulated wires cannot be directly buried in the wall, and a protective tube must be added to cause large-area leakage and endanger safety due to the aging of the spinning insulation.