The analysis of the causes of transformer oil leakage

 1,the seal quality reasons:At the scene of the collapse of the transformer terminals can be found at a time,leakage of oil terminal blocks most of fastening nut loose,install this doesn't mean that it did not tighten,with plane flange rubber gasket,for the first time after fastening tend to loose because of plastic deformation of ac induction motor the rubber gasket,need a second fastening.Transformer and our factory has been running for many years,there is no rubber gasket deformation problem,may explain why only is rubber gasket ageing lose elasticity,reducing the pressure on the surface of the flange connection.According to my years of generator generator set experience in maintenance,air isolation rubber gasket to run more than ten years should not have what problem.

Such as the transformer operation of our factory in nanjing,cichang has more than 20 years,did not find for porcelain set gasket aging oil leakage.Presumably liling porcelain production of transformer set gasket exist quality problems.2,environmental temperature change electricalmotor1.blogspot.com reasons:Refer to instruction for use of current transformer,transformer running environment temperature 40 ℃,the highest temperature is + minimum temperature of 40 ℃.Our factory area this summer outdoor certainly higher than 40 motor vehicle ℃,the highest temperature field measurement of the surface temperature is close to 50 ℃.After each part of the summer heat equipment thermal expansion,due to environment temperature drop after high temperature season,but all kinds of material shrinkage is not consistent with the temperature,cause the leakage of oil from the surface.This point in our plant is particularly prominent.

PLC control two pump start-up failure solutions to problems

Situation:in the double liang steam double-effect lithium bromide absorption air-conditioning unit,the use of omron PLC (PA204S C200HE-CPU42,power supply) to control the start of two pumps. When,in turn,start the two pumps,often led to the suspension of the power of the PLC,thus stop running program.Second,the detection of 1,use the meter to measure the voltage electric motor 12v 500w waveform of two pump ordinal startup PLC power PA204S ac voltage of the power supply change found:when did not start the electrical motor 12v 1000w pump,the voltage of the power supply is normal,when start the two pumps,instantaneous fell to the power supply voltage of 184 v,184 v and the duration of the above 25 ms,PLC to stop working,and to determine the effect of pump power of PLC.2,in order to solve this problem,respectively for the following tests: A) driving the pump first,delay around 10 s to start small pump,power supply voltage drop to about 190 v,the instructions first,pump makes instantaneous voltage drops,later start small pump,affect smaller,but it need to modify the PLC program.


B) because the pump power supply is turned by high tension line through a transformer,transformer capacity,can be considered a large capacity of transformer,may make the pump will be smaller influence on the PLC power supply voltage.C) in the PLC power supply termination a large capacitance,but the effect is not obvious.D) finally in one power supply transformer converted by a 220 v power supply to PLC,found that even in the start two pumps at the same time,PLC power supply voltage drop is only about 204 v,204 v,the can.Conclusion:as a result acmotortrading.blogspot.com of the PLC power supply is supplied with water pump in the same way,and the plant's transformer capacity is small,so in the start two pumps,caused the PLC power supply voltage drops below 85% of rated voltage,and duration of more than 10 ms,resulting in PLC detected power interruption,stop working. So the advice from the transformer converted one by one in the 220 v power to separate for PLC,which can solve the problem.