How To Distinguish Whether The Transformer Winding Is Copper Or Aluminum?
Filling copper with aluminum is a transformer that uses aluminum coils (half copper, half aluminum, aluminum foil) to pretend to be copper coils. It involves two major categories of products: three-phase dry power transformers and oil-immersed power transformers. Analysis believes that the biggest feature of this type of case is that the illegal behavior is very hidden. 1) Due to the special production process of transformers, even for transformers with aluminum coils, the terminals are connected with copper-aluminum joints and are also wrapped by insulating materials. When viewed directly, the exposed terminals are all made of copper. If you don't look at the processing process and only look at the appearance of the terminal and the finished product, it is difficult to distinguish between a copper coil transformer and an aluminum coil (semi-copper, half-aluminum, aluminum foil) transformer. Only the disassembled product can be confirmed. 2) If the transformer is disassembled, the problem involved is that the price is high, tens of thousands, or even hundreds of thousands. Disassembling the law enforcement will bear a great value risk, so that law enforcement officers will not dare to act rashly. 3) As long as the design of the transformer is reasonable, the existing technical testing methods cannot distinguish whether the transformer is a copper coil or an aluminum coil (semi-copper, half-aluminum, aluminum foil) through the product technical parameter test. 4) The illegal act of producing copper coil transformers filled with aluminum coils (semi-copper, half-aluminum, and aluminum foil) is only the knowledge of key individuals and is a "high-level secret" of the enterprise. So illegal behavior is very hidden.
The key points of investigation
The product labeling of "Transformer Product Model Compilation Method" puts forward the requirements on the model, distinguished by the letter code of the coil wire material: if the transformer coil is made of copper, the letter code is not marked in the transformer model, but other materials must be clearly indicated , Marked on the model. For example, the coil is made of aluminum, and the letter code "L" is marked in the model; the coil is made of semi-copper and half aluminum, and the letter code is "TL" in the model; the coil is made of aluminum foil, and the letter code is "CLB" in the model. In investigating such cases, law enforcement officers must identify the main line of the case. The main line is whether the material of the coil wire is consistent with the specifications and models.
Five key checkpoints should be controlled when grasping the main line. According to the transformer production process, the five key points are coil winding, transformer assembly, transformer test, finished product storage, and transformer sales. 1) Coil winding workshop. Grasp the on-site evidence of making aluminum (half copper, half aluminum, aluminum foil) coils, and collect first-hand materials such as processing drawings and plan sheets. Even if there is no aluminum (semi-copper, half-aluminum, aluminum foil) coil phenomenon on site, it cannot be given up. Check the raw material warehouse, check whether there are records of paper-clad aluminum wire or aluminum foil in and out of the warehouse. If so, check the inbound and outbound quantities, specifications and models, so that they can be checked with the next process. 2) Transformer assembly. All the components of the transformer passed from the previous process are assembled here. Whether the transformer coil is a copper coil or an aluminum coil (half copper, half aluminum, aluminum foil), it is clear that the transformer needs to be coded (serial number) to distinguish. Check the number of transformer assembly, query the code (serial number) arrangement rules, and classify statistics for checking with the custody account. 3) Inspection. Transformers assembled in the production workshop must be tested on a single unit, and the test qualified and stamped with the "test qualified seal" before leaving the factory. The test report should be accompanied by the transformer, and the content of the test report stub is consistent with the test report of the transformer. If aluminum coil (semi-copper, half-aluminum, aluminum foil) transformers are sold as copper coil transformer specifications, the specifications and model columns in the inspection report must be filled in the specifications of copper coil transformers in accordance with the "leader's instructions", and the product code (serial number) corresponds to the front and back , Will not change, transformer specifications and models are often "transformed" from this. 4) Finished product library. For aluminum coil (semi-copper, half-aluminum, aluminum foil) transformers, in which specifications and models are put in, the quantity in the warehouse, and what is the situation out of the warehouse, according to the specifications and models, find out the contradictions in the link from production to warehousing, and see the storage How to distinguish between the staff. It is worth noting that the transformer with the same code (serial number) is made of aluminum coils (semi-copper, half-aluminum, aluminum foil) in the production process, but turns into a copper-coiled transformer in the finished product storage process. Many phenomena can be reflected in the storage account. Out: Some companies use aluminum coil (half copper, half aluminum, aluminum foil) transformers to enter the warehouse according to aluminum coils (half copper, half aluminum, aluminum foil) transformers, and out of the warehouse according to copper coil transformers; some aluminum coils (half copper, half aluminum, Aluminium foil) transformers are entered as copper coil transformers when entering the warehouse. The records of aluminum coil (half copper, half aluminum, aluminum foil) transformers are not available in the entire account; some aluminum coil (half copper, half aluminum, aluminum foil) transformers are stored without nameplates, only stickers Coding, to distinguish whether the transformer coil is copper, aluminum or half-copper, half-aluminum, and aluminum foil. For example: "0+year and month + serial number" for copper coil transformers, "1+year and month + serial number" for aluminum coil transformers, "2+year, month + serial number" for half copper and half aluminum coil transformers, and "3+" for aluminum foil transformers Year and month + serial number" and so on, there are many tricks.
