The shell should be protective zero or grounding protective measures.
Safety and technical aspects of the basic requirements of electrical equipment
Statistics of electrical accidents show that due to structural defects in electrical equipment, installation quality is poor, can not meet the safety requirements caused by a large proportion of accidents. Therefore, in order to ensure personal and equipment safety, in terms of safety technology for electrical equipment have the following requirements:
(1) exposed to the ground and personal easy to touch the charged equipment, should take reliable protective measures.
(2) The charged parts of the equipment should be kept at a safe distance from the ground and other charged parts.
(3) Power systems prone to over-voltage should have over-voltage protection devices such as lightning rods, lightning wires, lightning arresters and protection gaps.
(4) low-voltage power systems should be grounded, zero protection devices.
(5) the various high-voltage power equipment should be taken to install high-voltage fuses and circuit breakers and other different types of protective measures; low-voltage power equipment should be protected by the corresponding low electrical protection measures.
(6) In the installation of electrical equipment should be installed at the location of safety signs.
(7) According to the characteristics and requirements of certain electrical equipment, special safety measures should be taken.
Expanded Information
Electrical fires are usually caused by overheating due to aging insulation, loose joints, overloading, or short circuiting of electrical equipment. Especially in flammable and explosive places, the above electrical wiring hazards are more harmful. In order to prevent the occurrence of electrical fire accidents, fire prevention measures must be taken.
(1) often check the operation of electrical equipment, check whether the joints are loose, there is no sparks occurring, electrical equipment, overload, short-circuit protection device performance is reliable, equipment insulation is good.
(2) Reasonable selection of electrical equipment. There are flammable and explosive substances in the place, the installation of electrical equipment, should be selected with explosion-proof appliances, insulated wires must be sealed and laid in the steel pipe. Should be selected according to the level of explosion hazardous places, the installation of electrical equipment.
(3) Maintain a safe installation location. Maintain the necessary safety spacing is one of the important measures of electrical fire prevention. In order to prevent electrical sparks and dangerous high temperature caused by fire, where sparks and dangerous high temperature electrical equipment should not be stacked around flammable and explosive substances.
(4) Maintain normal operation of electrical equipment. Electrical equipment operation sparks and dangerous high temperature is an important cause of electrical fires. In order to control excessive work sparks and dangerous high temperature, to ensure the normal operation of electrical equipment, should be qualified by the training and assessment of personnel to operate the use and maintenance.
(5) Ventilation. Electrical equipment operating in flammable and explosive hazardous locations, there should be good ventilation to reduce the concentration of explosive mixtures. Its ventilation system should meet the relevant requirements.
(6) grounding. In the flammable and explosive hazardous places of grounding than the general place of high requirements. Regardless of its voltage, normal non-electrified devices should be reliably grounded in accordance with the relevant provisions.
Extinguishing rules
(1) electrical equipment fire, fire appliances, lines may be charged, in order to prevent the spread of fire and fire extinguishing electrocution accidents, electrical fires should immediately cut off the power supply.
(2) Because the production can not be stopped, or because of other needs do not allow power cuts, must be charged to extinguish the fire, you must choose non-conductive fire extinguishing agent, such as carbon dioxide fire extinguishers, 1211 fire extinguishers, dibromo-difluoro-methane fire extinguishers and so on to extinguish the fire. Firefighters must wear insulated shoes and insulated gloves when fighting fires.
(3) The shortest distance when extinguishing the fire. When using non-conductive extinguishing agent to extinguish the fire, 10kV voltage, the shortest distance from the nozzle to the charged body should not be less than 0.4m; 35kV voltage, the shortest distance from the nozzle to the charged body should not be less than 0.6m. If the water to extinguish the fire, the voltage of 110kV and above, the nozzle must be maintained more than 3m between the nozzle and the charged body; 220KV and above, it should be no less than 5m.