Classification and scope of power tools

Hand-held power tools can be divided into three categories according to their insulation and anti-contact motor energy, that is, category I tools, category II tools, and category III tools.

1. For general occasions (air humidity less than 75%), you can use Class I or Class II hand-held power tools.

1) The connection points between the metal shell and the PE wire should not be less than two;

2) Leakage maintenance should comply with the requirements for leakage maintenance in humid places, and it is necessary to select Class II or Class III hand-held power tools powered by safety isolation transformers. The use of Class I hand-held power tools is prohibited.

2. Request for setting of switch box and control box:

When using Class II and III hand-held Hitachi power tools on wet occasions, on metal frameworks and in narrow areas, except for normal occasions, the switch box and control box should be located outside of the homework and monitored.


3. For narrow occasions, it is necessary to choose the type Ⅲ hand-held power tool powered by a safety isolation transformer (boiler, metal container, trench, pipeline, etc.) when working.


4. When operating in a wet place or on a metal frame. Its metal shell can be connected with PE wire, when using metal shell type II hand-held power tool. And set up leakage maintenance.