1. The single-phase power cords of mobile electric machines and hand-held power tools must use three-core soft rubber cables, and the three-phase power cords must use four-core rubber cables; when wiring, the cable sheath should be inserted into the junction box of the equipment and installed. be fixed.
2. Check the following items before using power tools:
(1) The shell and handle have no cracks or damage;
(2) The protective grounding wire or the neutral wire connection is correct 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 in good condition;
(7) The mechanical protective device is in good condition;
(8) The rotating part is flexible.
3. The insulation resistance of the power tool should be measured regularly with a 500V megohmmeter. If the insulation resistance between the live parts and the casing does not reach 2MΩ, maintenance must be carried out.
4. After the electrical part of the power 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 machinery and tools should be equipped with separate switches or sockets, and a leakage current action protector should be installed, and the metal shell should be grounded; it is strictly forbidden to connect multiple devices at one gate.
6. The rated leakage operating current of the current-type leakage protector shall not be greater than 30mA, and the operating time shall not be greater than 0.1 seconds; the rated leakage operating voltage of the voltage-type leakage protector shall not be greater than 36V.
7. The operation switch of the electric appliance should be placed within the reach of the operator. When there is a sudden power failure during rest, get off work or work, the switch on the power side should be cut off.
8. When using a portable or mobile power tool, you must wear insulating gloves or stand on an insulating pad; when moving the tool, do not hold the wire or the rotating part of the tool.
9. When using Class III insulated power tools in wet or acid-containing sites and in metal containers, reliable insulation measures must be taken and special personnel should be set up to monitor them. Switches for power tools should be located within the reach of guardians.
10. The disk plane of the magnetic chuck electric drill should be flat, clean and free of rust. When performing side drilling or upward drilling, 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 firmly secured and the nut should be fastened before starting.
