Safe use of hand-held power tools
1. The use of power tools must pay attention to safety: (1) Reasonable selection of hand-held power tools: ① In general places, mouth-type power tools should be used. If you use tools of type i, you must have safety protection measures, such as installing leakage protectors, safety isolation transformers and other devices. Or the user must wear insulated gloves, wear insulated shoes or stand on an insulating pad (table). Insulation appliances must be qualified. ② Class I or class tools must be used in working places with good electrical conductivity, such as wet or metal frames. If you use a Class I tool, you must install a leakage protector with a rated leakage operating current not greater than 30 mA and an operating time not greater than 0.1 s. ③When working in narrow, well-conducted places such as boilers, metal containers, pipes, etc., use Class II tools. If you use tools, you must install a leakage protector with a rated leakage operating current not greater than 15 mA and an operating time not greater than 0.1s. When in use, the safety isolation transformer of class Ⅲ tools, the leakage protector of class Ⅱ tools and the control box and power connector of class Ⅱ and Ⅲ tools must be placed outside the workplace, and there should be a special person to monitor, if necessary Brake. ④ In special environments, such as damp heat, rain and snow, and environments with explosive or corrosive gases, the power tools used must meet the safety technical requirements of the corresponding protection level, or be carried out according to (2). Except for the above requirements for explosive gas locations , Must use explosion-proof power tools. (2) The selection of cables and socket switches must meet the following requirements: ① The single-phase power tool of the power cord of Class I tools must use a three-core waterproof wire, and the three-phase power tool must use a four-core multi-strand copper-core rubber-sheathed flexible cable or sheathed flexible wire, where the yellow and green two-color wires or the specified core In any case, it can only be used to protect the ground or connect the zero line, and cannot be used for other purposes. ②Waterproof wire, flexible cable or flexible wire and their matching plugs shall not be arbitrarily lengthened or removed. After use, the power tool must not be moved by the power cord. ③ Plugs and sockets of power tools must be matched with them, and they should be compatible with the rated current of the tools. At the same time, they should comply with the national standards for power tools. 2. Notes on hand-held power tools The use of hand-held power tools should pay attention to the following safety requirements: (1) The nameplate and performance parameters of the tool should be compatible with the conditions of use; (2) The protective cover, protective cover, handle and other protective devices of the tool must not be damaged, deformed or loose: (3) The power switch must not malfunction or be damaged, the installation must be firm, and the wiring must not be loose; (4) The power cord should be a rubber-insulated soft cable, a three-core cable for single-phase, and a four-core cable for three-phase. The cable must not be damaged or cracked, and there must be no connectors in the middle; (5) Class I equipment should have good zero connection or grounding measures, and the protective zero line should be separated from the working zero line. The protective zero wire (or ground wire) should be a multi-stranded soft copper wire with a cross-sectional area of ??0.75 ~ 1.5 mm 'or more. The protective zero wire (ground wire) is preferably in the same sheath as the phase wire and the working zero wire; 6) Use Class I hand-held power tools should be equipped with insulating appliances; (7) The insulation resistance is qualified, and the insulation resistance between the live part and the accessible conductor is not less than 2 MΩ for Class I equipment and not less than 7 MΩ for Class II equipment; (8) Install leakage protection devices as needed: (9) Class I and Class II hand-held power tools shall not reduce the safety technical indicators determined by the original design after repair; (10) Cut off the power supply in time and keep it properly.