1, insulation is different: Class I appliances have working insulation. Class II such appliances using double insulation or strengthen the insulation requirements.
2, grounding is different: Class I have grounding terminals and grounding wire must be grounded and zeroed. A class of electrical equipment needs to be grounded, grounding wire inspection is also more important than the phase line inspection, phase line failure equipment does not work, it is easy to find, grounding wire breakage, no effect on the normal operation of the equipment, once an electrical accident occurs, it will cause electric shock or even death. Class II appliances have no grounding requirements.
3, the wire color is different: Class I appliances grounding wire must be used for the appearance of yellow and green two-color copper core insulated wire. class II appliances are not.
Expanded information:
Precautions for the use of household appliances:
1,? Household appliances should not be placed in damp, heat sources, flammable materials, dusty places.
2, household appliances in the process of operation, shall not use wet hands to touch the switch or its metal shell, not to mention touching the electrical components.
3, like hairdryer, soldering iron and other electrical appliances used by hand, do not wrap the wire around the hand or small arm, cut off the power supply, do not pull the cord by hand to pull out the plug.
4, the use of the human body to contact the electric apparatus, to have overheating protection device. If there is an abnormal odor and noise, should immediately cut off the power supply, check the cause of the anomaly.
5, to frequently check the power of the larger electric heating appliances power leads, shaking head, socket, found that the aging, the insulation degree of decline to be replaced in a timely manner.
Baidu Encyclopedia - Class II Electrical Appliances
Baidu Encyclopedia - Class I equipment