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首先，我电气技术不咋地，导致不能找到关键点；其次，这个英文实在有难度。。。大家帮忙分析下，到底怎么回事？ The lamp bulb explosived and fire happened at 12.30’ this morning , the reason has three point. First point: our power system of b12 transformer is grounding on A phase at 400V side , normal condition the voltage to grounding : A-PE-------220V / B-PE-----220V/C-PE-----220V/ N-PE-----0V.A-N--------220V/ B-N--------220V/C-N-----220V. Now the A phase is grounding , the voltage : A-PE-------0V / B-PE-----380V/C-PE-----380V/ N-PE-----220V. A-N--------220V/ B-N--------220V/C-N-----220V. Second point: in b08 warehouse we use one breaker to provide power for this area lighting ( total 16 set lamp), some lighting in this area is also grounding , the breaker in b08 lighting panel is trip , this breaker switch N and B phase . Third point: today the warehouse people wanted to check the storage in this area B08, but no lighting , so call utility people Mr chen xin tao to check the lighting , Mr chen switched on this breaker but tripped again, so he disconnected phase wire of power supply cable from terminal body , after he disconnected nature wire of power supply cable and connected this wire to phase terminal body, as we know the low power side of B12 transformer is grounding in somewhere, so voltage of this phase terminal body to grounding is 380V , just the power cable for this area lighting , phase wire is grounding also and nature wire is good , when Mr Chen switched on the breaker again , the 380V voltage send to lamps in this area and go to the grounding , very short time all lamp bulbs in this area were broken and two bulb explosived and damaged glass fall down with high temperature , the very hot glass fall down to plastic of big bag to produce the fire , when Mr Chen arrived this area from lighting panel , the fire already happened , even on the middle of way he had heard the noise of explosive , first he used the fire extinguisher to cancel the fire and called the duty electrical . Suggest : 1, the duty electrician should take care of the insulation of workshop transformer , even one point of 400v side is grounding , the voltage for all power system will move , the B12 transformer loads for b18 and b24 and b08 and construction life area, the transformer dispatch power to many points, some time it is very difficult to check the grounding point when the insulation is very low. Maybe we can think to add separator transformer ( 400v 3p/380v 3p+n) only for warehouse lighting. 2. this kind of lighting is not safety for warehouse because each bulb with 250W, it is very hot when running, on any protection for the bulb falling down, maybe we need change all lighting( try LED or bulb with cover). Best regards. | 
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发表于 2011-11-8 18:40
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