The Central Electricity Authority (CEA) has released new draft guidelines on the periodicity of type tests for major equipment across the power value chain.
A key proposal is to exempt transformers from repeating short-circuit tests solely due to changes in bushing or on-load tap changers (OLTC), provided these components have equal or superior ratings and have successfully passed type tests per IS/IEC standards.
The guidelines, titled “Guidelines for the Periodicity of Type Tests for Major Equipment used in Electrical Power System,” aim to standardize the frequency
of type tests, reduce unnecessary repetitions, and prevent congestion in testing facilities. Covering 63 types of equipment, the guidelines prescribe a 10-year minimum validity for type-test results if there is no alteration in design, materials, manufacturing process, or quality plans. Certain equipment, such as outdoor circuit breakers, gas-insulated switchgear (GIS), and ring main units (RMU), may have a 15-year test periodicity.
Type-tests, also known as proof tests, are design validation checks conducted on representative units rather than every individual unit, to meet quality assurance requirements.
CEA’s revised guidelines, open for stakeholder feedback until November 29, 2024, address prior inconsistencies in test periodicity across the generation, transmission, and distribution sectors, succeeding the 2022 guidelines on type test validity.