The Central Electricity Authority (CEA) on March 14, 2022 has issued guidelines for Type Tests for Major Equipment in Power Sector.
The objective of the guidelines are as followed:
a) To reduce the repeatability of tests, wherever possible: Specifying validity period of Type Test would ensure that the equipment need not be tested again and again unnecessarily if no major change has been introduced in the basic design/ technology/ material/ mechanical construction/ functionalities of the equipment/performance characteristic/ manufacturing process of the equipment. This would help in saving cost as well as time of all the stakeholders involved (i.e. manufacturers/ vendors/ utilities, etc. and in turn the end consumer as well).
b) To avoid overloading of testing facilities: It is often observed that certain testing facilities are overburdened due to non-optimal utilization of testing facilities spread across the country. Specifying the validity of Type Test(s) would reduce frequency of tests on similar equipment and hence reduce burden on the existing laboratories.
c) To avoid discrepancy in validity period of Type Test(s) being accepted or followed by various manufacturers or utilities and set uniform guidelines for all equipment manufacturers and procurers across the country.
• Guidelines specifically applicable to Hydro Power Sector
i) The latest CEA (Technical Standards for Construction of Electrical Plants and Electric Lines) Regulations shall be also complied with for ensuring the minimum technical requirements for construction of Hydro- Electric Generating Stations.
ii) The design of turbine/ pump-turbine/ reversible turbine along with its various components/ parts/ subassemblies varies on the basis of various parameters such as available head, discharge, dimension of water conductor system, capacity etc. to achieve an optimum performance and efficiency, and hence are specific to the project & tailor-made. Not only the type of turbine (Kaplan/ Francis/ Pelton, etc.) differ based on the available head, but various components of a particular turbine, viz. runner, guide apparatus, stay and guide rings, head cover, turbine shaft, shaft seal, bearings, governor system, etc. differ depending upon the requirements of different projects. As such, it is not possible to specify uniform Type Test validity period for different types of turbine/ pump-turbine/ reversible turbine along with its various components/ parts/ subassemblies.
Hence, only those components of turbine auxiliaries are included for which Type Test validity could be specified for a longer period and which don’t undergo major changes.
iii) The design of Synchronous/ Asynchronous Machine/ Generator-Motor along with its various components/ parts/ sub-assemblies depend on various parameters such as MW rating, Voltage level, Current Level, specific speed, number of poles, head & type of turbine used, run-away speed etc. Similar to the case of turbines, different types of generators (umbrella, semi-umbrella or suspended type) are selected depending upon the project requirements. Further, their components such as rotor, stator, windings, shaft, bracket, bearings, etc.
are uniquely designed for each project. As such, it is not possible to specify uniform Type Test validity period for different types of Generators along with its various components.
