Classification of electrical appliance structure types, what is the first category and what does the second category mean?

1 class: it has working insulation, grounding terminal and grounding wire, and it is required to be grounded or connected to zero. The grounding wire must be a yellow-green copper conductor, and the contact resistance should not be greater than 0. 1 ohm, such as a refrigerator.

Class 2: This type of electrical appliance adopts double insulation or reinforced insulation, and there is no grounding requirement. In addition to working insulation, there is independent protective insulation or effective electrical isolation. This kind of electric appliance has high safety and can be used for electric blankets and other appliances that contact with human skin.

Class 0: This kind of electrical appliance only requires the live part to be isolated from the shell, and there is no grounding requirement. This kind of electric appliance is mainly used in places that people can't reach, such as the rectifier of fluorescent lamp.

0 1 class: this kind of electrical appliance has industrial insulation and can be grounded or ungrounded with grounding terminals. It can be used in a dry environment (there are wooden floors indoors) and grounded, such as an electric soldering iron.

Category III: Use various electrical appliances in safe voltage (below 50 volts), such as razors and electric blankets. Safe voltage products must be used in an environment that cannot be safely grounded and is not dry.

Extended data

Use classification

1, control electrical appliances: electrical appliances used in various control circuits and control systems, such as contactors, relays, motor starters, etc.

2. Main control electrical appliances: electrical appliances used to send action instructions in the automatic control system, such as buttons, travel switches and cam switches.

3. Protective electrical appliances: electrical appliances used to protect circuits and electrical equipment, such as fuses, thermal relays, various protective relays, lightning arresters, etc.

4. Executive appliances: refers to electrical appliances used to complete certain actions or transmission functions, such as electromagnets and electromagnetic clutches.

5. Power distribution appliances: electrical appliances used to transmit and distribute electric energy, such as high-voltage circuit breakers, disconnectors, knife switches, automatic air switches, etc.

Baidu encyclopedia-second class electrics

Baidu encyclopedia-electrics