CEA Mandates Strict Use Of Standard Transformer Specifications For Power Utilities

The Central Electricity Authority (CEA), under the Ministry of Power, has issued a formal letter to power utilities across India, stressing that the use of standardized transformer specifications is now mandatory and must be strictly followed. In its communication dated January 24, 2026, the CEA reminded utilities that the “Standard Specifications and Technical Parameters for Transformers and Reactors (66 kV and above voltage class),” first issued in April 2021, have since become part of binding law.

According to the CEA, these standards are now enforceable under Regulation 46(1)(a) of the CEA Regulations, 2022, which were officially notified on December 23, 2022. This means all power utilities are legally required to follow the prescribed transformer ratings and technical parameters while planning, procuring, and tendering transformer equipment.

The main aim of this standardization is to bring greater efficiency and uniformity to the Indian power sector. By adopting common designs and ratings, the CEA seeks to simplify procurement processes and reduce the time taken for delivery of transformers. Uniform specifications also help ensure the use of proven engineering practices and consistent quality standards across projects. In addition, standardization is expected to create a level playing field for transformer manufacturers, encouraging fair competition and improving transparency in the bidding process.

However, the CEA has observed that several utilities are still issuing tenders with non-standard transformer ratings. The authority has clearly stated that this practice is in direct violation of the 2022 Regulations. It has also highlighted the negative impact such deviations have on the industry. When non-standard equipment is ordered, manufacturers are required to create new designs and carry out fresh testing, including type tests and dynamic short-circuit tests. This leads to higher costs and longer delivery timelines. In many cases, these customized requirements discourage manufacturers from participating in tenders, resulting in fewer bidders and reduced competition.

To avoid these issues, the CEA has advised all utilities to strictly follow the approved standard ratings and technical parameters while preparing new tenders. The standardized norms apply to both Power Transformers and Generating Transformers for voltage levels of 66 kV and above.

The letter also includes a detailed list of approved transformer ratings in Annexure-I. For example, standard auto transformers include ratings such as 500 MVA at 765/400 kV and 315 MVA at 400/220 kV. Power transformers have been standardized across a wide range, from 160 MVA at 220/66 kV down to 12.5 MVA at 66/11 kV. Standard ratings have also been specified for generator transformers used in thermal power plants, with single-phase units ranging from 200 MVA to 315 MVA.

The communication, signed by Chief Engineer N.R.L.K. Prasad, was sent to chairmen and managing directors of major transmission and generation utilities across almost all Indian states, including Karnataka, Maharashtra, West Bengal, and Uttar Pradesh, as well as central entities such as NTPC, NHPC, and NPCIL. Utilities have been encouraged to download the complete manual from the CEA website to ensure full compliance with the regulations.