Medical care can be described as “seeing, smelling, asking, cutting”, while electrical maintenance can be summarized as ten diagnostic methods。
I. Look
After taking over a malfunctioner, remove the frequency transformer's shell and clean up the sanitation, first observing the shape, integrity, etc. Of the relevant metaware on the circuit board with targeted eyes, depending on the type of failure of the transformer. This method is very useful for initial judgements such as charge resistance, filter electrolytic capacitors, igbt/flow bridge modules and even pcb circuit boards. As shown in figure i, the display of screen values during the use of a brand 75 kw variable was sporadic; the main plate exported dc10v power supply was intermittently broken. The reason for the failure was immediately found in the pen after the machine was removed - the switch to the main plate +15v power mainway caused by the burning of the pcb plate by welding
Ii. Listen
This approach is primarily aimed at three aspects of the mutator: the first is to determine the normality of the straight-flow carrier charge relay/contact inhaling, which is important for the resolution of pressure failure in the operation of the mutator. The sound of the transformer used to listen to the switch power is also effective for the initial determination of overloading of the switch power component. And finally, it's listening to the frequency-dispersed fan operation。
Iii. Touch
Following a failure of the transformer and power outages, the machine is quickly dismantled and protected by the associated electrons on the internal circuit board of the finger-toucher, ic integration blocks, etc. Once it becomes apparent that some of the components are rising at the same temperature, the fault must be in the body or the line around it
Iv. Pressure
Welding malfunctions of certain elements in internal circuits may occur when good and bad work occurs in the work of the frequency transformer. For some finely organized and numerous ics, it is not easy simply to observe whether there are problems. At this point, we may wish to use insulation plastic/wood rods (the use of metal articles that conduct electrical power is strictly prohibited) to press the element suspected under pressure, as appropriate, in a state of electrical penetration. This method is effective for the exclusion of small stickers, particularly ic, but must be operated in a way that is sensitive to electrocution and short circuits。
V. Knock
This method is complementary to the fourth test method, which, after all, can only be effective for small adhesive components, while it is not easy to operate for some high-power electrons or for a high-pressure-risk line segment. We can switch this to a knock, using insulation tools to strike properly near the suspected failure point, which in most cases can quickly lock the target. Figure iii shows the welding points of the components detected using this method that cause an intermittent over-pressure failure on a small-capacity variable
Vi. Volume
This method is mainly based on universal scale testing and, for the time being, more digital. About 65 per cent of all types of malfunctioning were addressed using a universal meter. With regard to the use of universal scale measurements, i am confident that a wide range of electrician friends can master it, and i would like to stress only one point: because of the high-pressure energy components inside the mutator, it's hard to use the watch until the power is out and the power is discharged before the line is measured
Monitoring
When we're done with the millimeter, let's go over the measurements. It refers to testing using oscilloscopes capable of visual displaying wave patterns. The use of oscilloscopes is generally directed to the six-way reverse pulse signal of the mutator (the brake power tube/module is driven by a switch, without the need for oscilloscope detection) for the exclusive maintenance of the transformer. When using oscilloscopes, emphasis is placed on whether the waveform of the signal is normal enough to meet the work requirements; and whether the driving signal range, frequency range, etc., meets the promotional requirements. This maintenance method is indispensable for the overhaul of the reverse power tube/module after burning
Viii. Short
The method is short-term. In the course of separate electrical overhauling of pulsed power lines, especially when the fm/ipm repair was removed as a result of damage, it was often not possible to properly open the light because of module damage or removal of chips with igbt/ipm failure detection capabilities such as the driver, a316j. At this point, a guidance line is required to link elements (mostly high anti-pressure diode anode) for igbt/ipm failure detection to the direct-flowing back end of the band (with a mark n or gnd) in order to defraud the main controller of the frequency transformer so that it believes that the power module is complete and that the drive pulse signal can be sent properly。
Ix. Discontinued
Break-off-off. You all know that the internal circuits of the mutators contain a number of protections for themselves or for loads, and we can use break-off/disconnection methods to determine maintenance in case of problems with these protections。
Example: however, all variants contain output end current monitoring protection. Some products, however, are very unscientific in their design of the function — failure to make it clear exactly what the problem was, which caused the maintenance staff to suffer. In response to this situation, we can take a case-by-case approach that separates the current sensor/flow detection subunits used for each phase of detection from the subsequent comparative circuit, and the point of failure (some types require manual repositioning in order to clear the malfunction). This also applies, of course, to the overhaul of protected lines such as temperature。
X. Release
Put it out. It contains electrolytic capacitors of various specifications and capacities, which are very high in relation to the probability of malfunctioning of the transformers due to reduced capacity. For the detection of these capacitors, general maintenance staff are more likely to perform overhauls by means of visualization and electromechanical gauge measurements, but both have certain limitations. For this purpose, i use incandescent light bulbs/small beads, which are compared with discharge tests once the object has been charged. This method provides an intuitive comparison of the capacity of the object, which, according to me, is more than 80% effective. This label, called 50v 220uf, is identified by the discharge detection method。
In the application of frequency transformers, long-term, safe and stable operation can only be achieved if the requirements of their design work and conditions of normal use are met. When used in poor working environments, increased attention is given to the daily maintenance and overhaul of transformers and to improving the environment for their use and the volatility of loads. In order to ensure the reliable, smooth and safe performance of the transformer, the purpose is to operate at speed, save electricity and reduce maintenance costs. We're looking at ten ways to fix the frequency
