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 disguise as copper coils. It involves two categories of products: three-phase dry-type power transformers and oil-immersed power transformers. The analysis believes that the biggest feature of such cases is that the illegal acts are very concealed.

1) Due to the special production process of the transformer, even the transformer with aluminum coil, its terminals are connected with copper-aluminum joints and wrapped with insulating materials. Directly looking, the exposed terminals are all made of copper. If you don't look at the processing technology, but only look at the appearance and finished products of the terminals, it is difficult to distinguish between copper coil transformers and aluminum coil (half copper, half aluminum, aluminum foil) transformers. Only disassembled products can be confirmed.

2) If the transformer is removed, the problem is that the price is high, tens of thousands or even hundreds of thousands. Dismantling law enforcement will bear a great risk of value, and law enforcement officers dare not act rashly.

3) As long as the design of the transformer is reasonable, the existing technical test methods cannot distinguish whether the transformer is a copper coil or an aluminum coil (half 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, semi-aluminum, aluminum foil) is only the knowledge of key individuals, and is the "high-level secret" of the enterprise. So the violation is very covert.

Investigation focus

The product labeling of the "Measures for Compiling Transformer Product Models" puts forward requirements for the model, which is distinguished by the letter code of the coil wire: if the transformer coil is made of copper, the letter code is not marked in the transformer model, but other materials must be clearly marked. marked on the model. For example, the coil is made of aluminum, and the letter code "L" is marked in the model; the coil material is half copper and half aluminum, and the letter code is "TL" in the model; the coil is made of aluminum foil, and the letter code in the model is "CLB". When investigating such cases, law enforcement officers must determine the main thread of the case. It mainly depends on whether the material of the coil wire is consistent with the specification and model.

Grasp the main line to control five key levels. According to the transformer production process, the five key points are coil winding, transformer assembly, transformer testing, finished product storage, and transformer sales.

1) Coil winding workshop. Master the field evidence of making aluminum (half copper, half aluminum, aluminum foil) coils, and collect first-hand information such as processing drawings and floor plans. Even if there is no aluminum (half copper, half aluminum, aluminum foil) coil phenomenon on site, it cannot be abandoned. Check the raw material warehouse and check whether there is a record of paper-wrapped aluminum wire or aluminum foil entering and leaving the warehouse. If there is, check the quantity, specification and model of inbound and outbound storage, so that the next process can check it.

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) obviously needs to be coded (serial number) to distinguish the transformer. Check the number of transformer groups, query the code (serial number) arrangement rules, classify statistics and check the custody account.

3) Check. Transformers assembled in the production workshop must be tested on a single unit, and they can be shipped out after passing the test and stamping with the "Test Qualified Seal". The test report should be attached to the transformer, and the content of the test report stub is consistent with the transformer test report. For example, transformers with aluminum coils (half copper, half aluminum, aluminum foil) are sold according to the specifications of copper coil transformers. The specification and model column in the inspection report must be filled in with copper coil transformer specifications according to the "Leader's Instructions", and the product code (serial number) is positive and negative. One correspondence will not change, and the transformer specifications and models are often "transformed" from this.

4) Finished product library. Aluminum coil (half-copper, half-aluminum, aluminum foil) transformers, storage specifications, storage quantities, and storage conditions. Find out the contradictions from production to storage according to the specifications and models, and see how the storage personnel distinguish. It is worth noting that transformers with the same code (serial number) are made of aluminum coils (half copper, half aluminum, aluminum foil) during the production process, but become copper coil transformers when the finished products are put into storage.

Outbound: Some enterprises use aluminum coil (half copper, half aluminum, aluminum foil) transformers for storage as aluminum coil (half copper, half aluminum, aluminum foil) transformers, and out of the warehouse for copper coil transformers; some aluminum coils (half copper, half aluminum, , aluminum foil) transformers are stored as copper coil transformers when they are put into storage. The records of transformers with aluminum coils (half copper, half aluminum, aluminum foil) are incomplete; some aluminum coil (half copper, half aluminum, aluminum foil) transformers are stored without nameplates, but only with codes to distinguish whether the transformer coils are copper, aluminum or half. Copper, semi-aluminum, aluminum foil. For example: the copper coil transformer is "0+year month+serial number", the aluminum coil transformer is "1+year month+serial number", the half copper half aluminum coil is "2+year month+serial number" transformer, the aluminum foil transformer's "3+" year month + serial number" and so on, there are many tricks.