Impact drill is mainly suitable for the concrete floor, wall, brick, stone, wood and multilayer material impact on the punch; Also can be conducted on wood, metal, ceramic and plastic drilling and tapping and equipped with electronic speed equipment for cis/reverse, and other functions. Small make up today to introduce the common types of impact drill, drill and regular drills are hand-held power tools. Such tools according to get an electric shock protection methods can be divided into three categories. Ⅰ tools, to prevent the electric shock protection, not only rely on basic insulation itself, but also contains an additional safety precautions, such as the leakage protector, safety isolation transformer, insulation or operators wear insulating gloves, shoes, etc. Ⅰ tools requirement between electrically live parts and the shell has M Ω insulation resistance (Measured with V megohmmeter, hereinafter the same)。 Ⅱ tools, to prevent the electric shock protection, not only depend on itself, the basic insulation and tools also provide additional safety precautions double insulation or reinforced insulation and equipped with protection grounding or measures depend on the installation conditions. Ⅱ tools requirement between electrically live parts and the shell with M Ω insulation resistance. In the obvious parts of the tool with Ⅱ class structure symbol 'back'. Ⅲ tools, to prevent electric shock protection by means of the safety voltage power supply does not produce tools within than safe low voltage and high voltage. Ⅲ tools requirement between electrically live parts and the shell with M Ω insulation resistance.
