【 Weak current College 】 electrical fire---transformer, distribution equipment for fire-Power By 【 China power house network 】

When the power supply to users, in order to reduce transportation energy loss, the first issue of voltage rise of generator, then uses the voltage transmission line to the transformer, distribution, reduced to the user the required voltage, so that users can use. Transformers, power distribution unit is the transformation of voltage and electrical energy distribution installations, it consists of a transformer. Power distribution equipment, control equipment and other auxiliary facilities, etc. Commonly used transformer is the oil-immersed power transformers, dry-type transformer also gradually use. Power distribution unit generally installed in the transformer, distribution, oil circuit breakers is the main part of the control device. An oil-immersed power transformer 1. fire risk (1) transformer internal insulation liner and support, most of the wood, cardboard, cotton yarn, fabric and other organic combustible substances that have a large number of insulating oil wells. Transformer oil under high temperature or arc, fever and easy decomposition, precipitated some flammable gases, in the role of arc or spark extremely explosive and incendiary power outages throughout the region, affecting normal production, life, and resulting in significant losses. (2) due to the coil insulation ageing, oil or oil quantity is too small. Core insulation ageing. Repair accidentally rupture of dampness, insulation, etc. caused transformer failure protection system failure, leading to transformer burnout. (3) due to the bolt, welding is not strong, tap switch contact damage caused by bad, will produce localized high temperature or arc and cause a fire. (4) because the coil layer short, coil turn to turn short-circuit between phases, coils and close to the tank part of insulation breakdown, cause a fire or explosion. (5) the current transformers are introduced by overhead lines, easy to be generated from 1 lightning over-voltage, breakdown transformer insulation and fire. (6) of the magnetic circuit "' core fire." As a result of damage to the insulation between the silicon steel or iron bolt clamp casing makes the transformer iron loss increase rapidly warming but 1 "damages insulation fire. (7) transformer insulation pipe as the casing on crack, its surface area have oil decomposition of waste and water, acid and carbon particles, or, in case of excess voltage bushings and fuel tank cap room flashover occurs, arcing and cause a fire. (8) transformer oil spills, oil penetration, oil changes, it can cause dielectric strength reduction, produce a lot of heat and cause a fire. 2. fire precautions (1) the quality of the transformer must meet the technical requirements of manufacturers, pre-installation for insulation test and carefully review each part of the transformer is intact, look, the known good before installation. (2) transformers should fuse or relay protection equipment, its size should be equal to the maximum security to protect current transformer in short circuit and overload sometimes does not cause the fire line. Melt should be guaranteed the leads loop occurs when a short or overload may fuse. (3) various capacity of transformer thermometer should be installed and ensure that their sensitive and easy to use, to gauge the temperature of the transformer, the temperature rise shall not exceed 60.C. (4) more than 100 kW shall be equipped with oil transformers pillows and glass oil level indicator, and the oil level indicator should be engraved with the equivalent of a 20 ' oil ° C, 10-15 C, + 35 ' c, and so the oil surface temperature of sight, often to monitor the oil level not lower than the temperature of sight, and check the transformer oil penetration oil leakage, pay attention to check the fuel tank and casing are intact. (5) the transformer should be well ventilated, and keep the surrounding temperature not exceeding 35 ° c. Transformer capacity should be adapted to needs, which prohibited overload transports. (6) more than 1000 kW transformer should be installed to reduce the exhaust fuse in the transformer, preventing the tank explosion or burst. (7) transformer shell with equipment grounding grid connection, making it reliable grounding, the inlet should arresters, thunderstorm season should be checked carefully to prevent lightning fires. (8) an outdoor installation of transformer, conditional should set up specialized storage pool. Once the fire, the oil into the pit to avoid oil outflow to prevent explosions and proliferation. (9) indoor transformer should be set and the transformer heat vents, and set the accident of the oil drain pit facilities and oil gathering. The distance between adjacent transformer is less than 5 meters, explosion-proof partition be isolated to prevent the spread of fire. (10) after the transformer correctly according to the statutes, regular maintenance. If transformers seriously overloaded and should be replaced or enable standby transformers to relax. Second oil circuit breaker 1. fire risk (1) oil circuit breaker contacts to the surface of the reservoir is too low, tank oil level too high, the oil dielectric strength deterioration, operation, structural adjustment and interrupting capacity small, can affect the normal operation of power systems and fire. (2) oil circuit breakers and out of the line through the insulation sleeving, when insulating Sleeving with tank, the tank cover and oil tank sealing is not strict, dampness, fuel tank or tank unclean, insulating Sleeving with mechanical damage can lead to short circuit causing explosions or fires. 2. fire precautions (1) circuit breaker before installation should be strictly checked. Circuit breakers interrupting capacity should be greater than installation of the circuit breaker. Maintenance operation test should be conducted to ensure mechanical flexible, reliable, and adjust the same three-phase actions. (2) circuit breaker and the electrical circuit of the connection to close and available on the temperature of wax tablets observation of temperature. Contact damage should be reversed. Maintenance finished insulation test should be carried out by the specialist is responsible for the inventory tool to prevent tools fall into the tank caused a short circuit in the event of an accident. (3) oil circuit breakers into operation before, you should also check your insulation Sleeving and tank lid sealing performance, avoid dampness, causing the tank breaker explosion combustion. (4) oil circuit breakers runtime should regularly check the oil surface height, the oil level must strictly control in oil level indicator. Discovery of oil spills, oozing or abnormal sound, you should immediately reduce load or power outage maintenance, is strictly prohibited to force transmission. Three variable, substation 1. fire danger, some distribution the device contains a lot of flammable, explosive liquid. Gas, or contain strong corrosive liquids, high temperature and the arc function, can cause burning, explosion and other accidents. 2. fire precautions (1) high and low pressure electrical power distribution, high and low pressure electrical power distribution unit should be fire-resistant grade I and II. Low-voltage distribution, fire resistance etc.Level should not be lower than the levels, the use of concrete floors. Length is greater than 7 meters of high-voltage power distribution, and length is greater than 10 m low-voltage power distribution unit with at least two doors, and shall open outwards. Between adjacent distribution Chamber should not in General, such as gate door must be located, you should be able to open in both directions. Distribution, you can open the window, but you should take certain precautions, such as the set grid is not greater than 20 mm x 20 mm of barbed wire and the rain canopy, to prevent invasion of rain and snow and small animals. High and low voltage distribution equipment such as a layout in the same room, the device asks for the distance shall be not less than 1 m. (2) oil-immersed power transformer, the transformer Chamber should be fire-resistant grade level, building on the steel and cement are not easy to come by, you can use an independent three-level architecture of refractory grade. Capacity of 100 kW or more oil-immersed power transformer should be installed in separate transformers indoor. Indoor should have good natural ventilation and indoor temperature should not exceed 45 ° c. If the room temperature is too high, you can use mechanical ventilation. Ventilation equipment should be set grid is not greater than 10 mm x 10 mm of barbed wire and rain. Snow intrusive measures. Oil-immersed power transformer room, should not be located in the Interior, staff gathered or the hospital ward of above and below, or to both sides of the main exit. In the absence of special fire safety requirements of other civil architecture of the first layer you can set the oil-immersed power transformer room, but should not be set in place often stagnant water and toilets and bathrooms. At this point, a transformer room can only be set one-park immersed power transformers, and its capacity does not exceed 400 kW, also due to open door. (3) capacitors, high-voltage oil-immersed power capacitor rooms should be not less than the second-resistive rating of the building, room should have good natural ventilation. If natural ventilation does not guarantee that the room temperature is below 45 C, you should separate ventilation device, and take the rain, snow and small animals. High voltage capacitors should be set separately. 1000 Volt low voltage capacitor below can be set in the high and low voltage distribution indoors. Capacitors are not more than three layers of hierarchy, the lower surface on the bottom margin should not be less than 100 mm, capacitor shell adjacent width between at least 50 mm width of the pitch, the channel should not be less than 1 m. Capacitor charging pile head off the ground should be added below the 2.2 m when appropriate shielded facilities. Capacitors should be separate switch control, automatic discharge device and grounding device. Each capacitor should also be separate fuse to protect it. Capacitor inputs at run time, the indoor temperature should not exceed 45 C, the capacitor surface temperature should not exceed 55 C and indoor, equipment surfaces and stand cleaning, should always check the capacitor run, identify problems, timely processing and maintenance, repair, testing should be insulated. (4) acid battery compartment storage power he group should be installed in non-combustible material within the building's private room, with a certain degree of explosion pressure relief area, its Windows and doors, walls. Floor, ceiling should have ACID properties. Interior of natural ventilation conditions should be kept well and use of axial-flow ventilation equipment should be set up independently, the ventilation pipe is noncombustible material should be used. Indoor electrical equipment should be consistent with explosion-proof requirements, prevention of explosion caused by hydrogen on; through wall wires should be installed at the through-wall porcelain, holes you must use acidproof fireproofing material block. Rooms must be kept clean and not storing any fuel. Sour room should be set, SA reserves limited to day work. (5), the Interior and exterior power distribution unit should have a good lightning protection facilities and protection earthing or protect zero equipment, electrical equipment must be kept clean to prevent oil pollution caused by short circuit electrically conductive dust.