1, the first case: induction leakage. Electric motors, transformers, a class of electrical appliances, due to the existence of capacitance between the coil and the core, when energized, there will be a weak leakage current. This leakage current is small, there is basically no harm to the person.
2, the second situation: electrical equipment insulation decline, or breakdown. For example, water leakage caused by the washing machine insulation drop. This leakage situation is dangerous, must take measures to repair, exclude leakage failure can be.
3, the protection of the entire power system has two kinds of protection: protection of zero, and protection of grounding. The current power supply system, basically take the protection of zero. Regulations, the same system, not allowed to use both protective zero and protective grounding (easy to "strike voltage"). So you can not arbitrarily take the grounding wire.
4, check the leakage of household electrical equipment, to use the 500V shaking table test. Be sure to repair, exclude leakage faults, before you can rest assured that the use. In addition, it is best to install the use of leakage protector.
Expanded Information:
1, buy leakage protector should be purchased with the production qualification of the manufacturer's products, and product quality testing. Here to remind you: the market sales of leakage protector a lot of substandard products. 2002 October 28, the State Administration of Quality Supervision announced leakage protector product quality sampling results, there are about 20% of the products failed,
The main problems are: some can not be normal breaking short-circuit current, eliminating the fire hazards; some can not play a role in the protection of the person electrocuted; there are also a few Should not be tripped when tripped, affecting the normal use of electricity.
2, should be based on the scope of protection, personal equipment safety and environmental requirements to determine the leakage protector of the supply voltage, operating current, leakage current and action time and other parameters.
3, the power supply using leakage protector for hierarchical protection, should meet the upper and lower switching action selectivity. Generally on the level of leakage protector rated leakage current is not less than the next level of leakage protector rated leakage current, so that both sensitive protection of personal and equipment safety, but also to avoid overstep trip, reduce the scope of the accident check.
4, hand-held power tools (in addition to Class III), mobile household appliances (in addition to Class III), other mobile electromechanical equipment, as well as electrical equipment with a greater risk of electrocution, must be installed leakage protector.
5, construction sites, temporary lines of electrical equipment, should be installed leakage protector. This is the "construction site temporary electricity safety technical specifications" (JGJ46-88) in the clear requirements.
6, organs, schools, enterprises, residential buildings within the socket circuit, hotels, restaurants and guest houses in the guest room socket circuit, must also install leakage protector.
7, installed in the water supply lines and equipment and humidity, high temperature, metal occupancy coefficient and other conductive places, such as machining, metallurgy, textile, electronics, food processing and other industries, as well as boiler rooms, pump rooms, canteens, bathrooms, hospitals, etc., must be used to protect leakage protector.
8, fixed-line electrical equipment and normal production workplace, should be used with leakage protector power distribution box. Temporary use of small electrical equipment, should be selected leakage protection plug (seat) or socket box with leakage protector.
9, leakage protector as a direct contact protection supplemental protection (can not be the only direct contact protection), should be selected with high sensitivity, fast-acting leakage protector.
General environment selection action current does not exceed 30mA, action time does not exceed 0, 1s, these two parameters to ensure that the human body if electrocuted, will not make the electrocuted person to produce a pathophysiological danger effect. In the bathroom, swimming pool and other places leakage protector rated action current should not exceed 10mA.
In the electric shock may lead to secondary accidents in the occasion, the rated action current should be 6mA leakage protector.
10, for the electrical equipment does not allow power outages, such as public **** place of passageway lighting, emergency lighting, fire fighting equipment power supply, power supply for burglar alarm, etc., should be used to alarm leakage protector connected to the acoustic and optical alarm signals, notify the management staff to deal with the problem in a timely manner.
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