The Central Electricity Authority (CEA) has directed all state power utilities to strictly follow the ratings prescribed by it while floating tenders for transformers with a minimum voltage class of 66 kV.

In a letter to 61 state power utilities and power departments, the CEA said several utilities were not adhering to the standard specifications and technical parameters for transformers and reactors.

Tenders floated by utilities were specifying non-standard transformer ratings in violation of the CEA (Technical Standards for Construction of Electrical Plants and Electric Lines) Regulations, 2022.

The standard specifications were framed to simplify the procurement process, deliver faster, incorporate best design practices, ensure quality control and testing requirements, and place all manufacturers on a level playing field.

However, non-adherence to the standards was causing delays in transformer supply and compelling transformer manufacturers to design and test new-rated transformers. Non-compliance with the prescribed ratings increased the cost of such transformers due to new designs, various type tests, and dynamic short-circuit tests.

The CEA also highlighted that fewer transformer and reactor manufacturers were participating in the procurement tenders for such non-standard rating transformers, thereby reducing competition.

India’s power transmission sector has been facing supply chain shortages and higher procurement costs due to high demand for transformers and transmission components, including control relay panels, tower parts, insulators, and gas-insulated switchgear, leading to longer lead times for procurement.

The CEA, in a report, said transmission utilities had reported 17 failures of power transformers with a voltage of 220 kV or higher between January and June 2025. A large number of transformer failure incidents remained unreported, as many state and central transmission utilities and private utilities failed to share data.

The report raised concerns about many transformers failing in the first few years of service. It attributed transformer failures to normal aging, insulation system and bushing faults, system faults, transient overvoltage generated by the systems, and the absence of prudent maintenance practices.