As a leader committed to ethical manufacturing and product transparency, CHH Power closely monitors industry irregularities—among which “aluminum-as-copper” transformer fraud stands out as a deceptive practice. This fraud involves passing off transformers with aluminum-based coils (including half-copper-half-aluminum, aluminum foil, or full-aluminum designs) as premium copper-coil units, affecting both three-phase dry-type and oil-immersed power transformers. CHH Power’s analysis highlights the extreme concealment of this illegal act, while also outlining key investigation directions based on industry standards and production processes.
1. The Hidden Nature of Aluminum-as-Copper Transformer Fraud
CHH Power’s industry research identifies four core reasons why this fraud is difficult to detect, making it a persistent challenge for regulators and buyers:
- Terminal Disguise via Manufacturing Process: Even aluminum-coil transformers use copper-aluminum transition joints for terminals, which are then wrapped in insulating materials. To the naked eye, exposed terminals appear fully copper. Without observing the production process, distinguishing copper-coil units from aluminum/hybrid-coil ones based solely on terminal or finished product appearance is nearly impossible—confirmation typically requires disassembly.
- High Disassembly Risk Deters Law Enforcement: Disassembling a transformer incurs significant costs (tens of thousands to hundreds of thousands of yuan). Law enforcement agencies face substantial value risks if disassembly fails to confirm fraud, leading to hesitation in taking action.
- Technical Testing Limitations: With reasonable design, existing technical parameter tests (e.g., loss, efficiency) cannot differentiate between copper and aluminum/hybrid coils. This means standard performance inspections may not reveal the material substitution.
- Internal Secrecy Within Fraudulent Enterprises: The practice is limited to key personnel, treated as a “top-level secret” within the company. This lack of internal leaks further shields the fraud from external detection.
2. Investigation Core: Aligning Coil Material with Labeled Specifications
CHH Power emphasizes that investigations must center on a key principle: verifying whether the transformer’s actual coil material matches the specifications stated in its model, as mandated by the Transformer Product Model Compilation Method.
This standard clearly requires letter codes to distinguish coil materials:
- Copper coils: No letter code in the model.
- Aluminum coils: Marked with the letter “L”.
- Half-copper-half-aluminum coils: Marked with “TL”.
- Aluminum foil coils: Marked with “CLB”.
To uphold this principle, CHH Power recommends focusing on five critical checkpoints throughout the transformer production process—key areas where material substitution discrepancies typically emerge.
3. Five Critical Investigation Checkpoints in Production
(1) Coil Winding Workshop: Trace Raw Material Flow
This is the primary source of evidence for material substitution. Investigators should:
- Secure on-site evidence of aluminum/hybrid coil production, such as processing drawings, production schedules, or semi-finished coils.
- If no aluminum/hybrid coils are found on-site, check the raw material warehouse for inbound/outbound records of paper-insulated aluminum wires or aluminum foil. Cross-verify quantities and specifications with subsequent production processes to identify unaccounted-for materials.
CHH Power notes that legitimate manufacturers (like itself) maintain detailed, traceable records of copper wire purchases and usage—an absence of such records may signal fraud.
(2) Transformer Assembly: Cross-Check Serial Number Consistency
All transformer components (including coils) are assembled here, with each unit assigned a unique serial number for identification. Investigators should:
- Document the number of transformers assembled and clarify serial numbering rules.
- Classify and count serial numbers to cross-check with warehouse inventory records. Discrepancies (e.g., unrecorded serial numbers or mismatched material labels) may indicate that aluminum/hybrid-coil units are being assigned serial numbers intended for copper-coil products.
(3) Testing Phase: Scrutinize Report Authenticity
All finished transformers undergo individual testing; only those passing receive a “test qualification seal” before shipment. Fraudulent enterprises often manipulate test reports:
- If aluminum/hybrid-coil transformers are sold as copper-coil ones, test reports are falsified to list copper-coil specifications (often per “management instructions”).
- Investigators should verify that the serial number on the test report stub matches the finished product and that technical parameters (e.g., loss values) align with the labeled coil material. CHH Power’s in-house testing requires dual-signoff for reports, preventing such tampering.
(4) Finished Product Warehouse: Uncover Inventory Contradictions
Warehouse records often reveal material substitution through inconsistent inbound/outbound labeling. CHH Power highlights common red flags:
- Mismatched Inbound-Outbound Labels: Aluminum/hybrid-coil transformers are warehoused under aluminum-coil designations but shipped as copper-coil products.
- Missing Aluminum-Coil Records: All units are recorded as copper-coil transformers, with no trace of aluminum/hybrid-coil inventory.
- Coded Serial Number Tricks: Some enterprises use unmarked nameplates, only affixing coded stickers (e.g., “0+year-month-serial” for copper, “1+” for aluminum, “2+” for half-copper-half-aluminum, “3+” for aluminum foil) to internally track material types while deceiving external buyers.
CHH Power advocates for stricter industry oversight, including third-party material audits and standardized production record-keeping, to eradicate aluminum-as-copper fraud and protect market fairness.