What kind of power tools are hand drills? 1, 2 or 3?
You can see the cable plug, the aluminum shell is inserted three I tools, is grounded, the aluminum shell and some II tools, because it has a plastic insulation between the stator and the aluminum shell, so it is the installation of two wire plug.
I class: in the prevention of electric shock protection, in addition to relying on basic insulation, but also the need for zero protection.Class II: the tool itself has double insulation or insulation without the need to protect the ground.Class III: Powered by a secure, ultra low voltage power supply, no voltage higher than the safety supply voltage is generated within the tool.The above is the classification of insulation categories.
