2. Electrical System
2.5. Classification of electrical and electronic equipment according to the method PROTECTION AGAINST ELECTRIC SHOCK
GOST R IEC 536-94 specifies equipment classes.
The division into classes does not reflect the level of safety equipment, but merely points to the way in which to protect against electric shock.
- 3.1. class equipment 0
- Equipment in which protection against electric shock is provided by basic insulation, thus there is no electrical connection of exposed conductive parts, if any, to the protective conductor of fixed wiring. In the breakdown of basic insulation protection of the environment should be ensured (air, floor insulation, etc.).
- 3.2. Class I Equipment
- Equipment in which protection against electric shock is provided by basic insulation and connecting the exposed conductive parts, available touch, with the protective conductor of fixed wiring.
In this case, the exposed conductive parts, available touch can not be energized when an insulation fault after tripping adequate protection.
Remarks:
1. equipment designed for use with a flexible cable, these means include a protective conductor, which is part of the flexible cable.
2. If the standards for specific types of equipment allow to equipment whose construction is classified as I, it was equipped with a flexible cable with two conductors having the plug on the end that can not be put into a socket with protective contact, no such protection is provided by the main equipment insulation. This equipment must be provided with a clamp for connecting a protective conductor.
- 3.3. Class II equipment
- Equipment in which protection against electric shock is achieved by using double or reinforced insulation.
In Class II equipment has no means of protective earthing and protective properties of the surrounding medium is not used as a security measure.
Remarks:
1. In some special cases (for example, input terminals of electronic equipment) in the Class II equipment protective resistance can be provided if needed and its use does not reduce the safety level.
2. Class II equipment can be provided with means to ensure continuous monitoring of the integrity of protective circuits provided that these funds are an integral part of the equipment and insulated from accessible surfaces according to the requirements for Class II equipment.
3. In some cases it is necessary to distinguish the equipment of class II "completely isolated" and equipment "from the metal shell."
4. Class II equipment with the metallic shell can be provided with means for connection to the conductor sheath potential equalization only if this requirement is provided by the corresponding standard equipment.
5. Class II equipment to be functional in the ground supply device, different from the grounding device used for protective purposes, provided that the requirement to provide suitable equipment standard.
- 3.4. Class III equipment
- Equipment in which protection against electric shock is based on the power of the source of SELV and which does not cause voltage above the safety extra-low voltage.
Remarks:
1. In the equipment class III should not be ground clamp.
2. Equipment Class III with a metal shell is allowed to supply means for connection with the sheath potential equalizing conductor, provided that the requirement to provide suitable equipment standard.
3. Class III equipment is allowed to supply the grounding device in order to function, different from the grounding device used for protective purposes, provided that the requirement to provide suitable equipment standard.
Comments
Commenting, keep in mind that the content and the tone of your messages can hurt the feelings of real people, show respect and tolerance to his interlocutors, even if you do not share their opinion, your behavior in terms of freedom of speech and anonymity offered by the Internet, is changing not only virtual, but real world. All comments are hidden from the index, spam control.