1. The single-phase power cord of mobile electric machines and hand-held electric tools must use three-core soft rubber cables, and the three-phase power cord must use four-core rubber cables; when wiring, the cable sheath should be inserted into the junction box of the equipment and be fixed.

　　2. Check the following items before using electric tools:

　　(1) The casing and handle are free from cracks and damage;

　　(2) The connection of the protective grounding wire or the neutral wire is accurate and firm;

　　(3) The cables or cords are in good condition;

　　(4) The plug is in good condition;

　　(5) The switch action is normal, flexible and free of defects;

　　(6) The electrical protection device is intact;

　　(7) The mechanical protection device is intact;

　　(8) The rolling part is flexible.

　　3. The insulation resistance of electric tools should be measured regularly with a 500V megohmmeter. If the insulation resistance between the live parts and the shell does not reach 2MΩ, maintenance must be carried out.

　　4. After the electrical part of the electric tool is repaired, the insulation resistance measurement and insulation withstand voltage test must be carried out. The test voltage is 380V and the test time is 1 minute.

　　5. The electrical circuit connecting electric machines and tools should be provided with a separate switch or socket, and a leakage protection device should be installed, and the metal casing should be grounded; it is strictly forbidden to connect multiple devices with one gate.

　　6. The rated leakage operating current of the current type leakage protector shall not exceed 30mA, and the action time shall not exceed 0.1 second; the rated leakage operating voltage of the voltage type leakage protector shall not exceed 36V.

　　7. The operation switch of the electric motor should be placed within the reach of the operator. When there is a sudden power failure during rest, work or work, the power side switch should be cut off.

　　8. When using portable or mobile electric tools, you must wear insulating gloves or stand on insulating mats; when moving tools, do not hold wires or rolling parts of tools.

　　9. When using class III insulated power tools on wet or acid-containing sites and in metal containers, reliable insulation measures must be taken and special personnel should be supervised. The switch of the electric tool should be located within the reach of the guardian.

　　10. The disk plane of the magnetic chuck electric drill should be flat, clean, and rust-free. When drilling sideways or upside down, measures should be taken to prevent the drill body from falling after power failure.

　　11. When using an electric wrench, the counter torque fulcrum should be firm and the nut should be fastened before starting.