IEC 62975-2021 pdf Natural esters – Guidelines for maintenance and use in electrical equipment

3.1 local regulations regulations pertinent to the particular process in the country concerned Note 1 to entry: These regulations may be defined by local, regional or national legislation or even by the owner or operator of the equipment itself. They are always to be considered as the most stringent of any combination thereof. It is the responsibility of each user of this document to familiarize themselves with the regulations applicable to their situation. These regulations shall refer to operational, environmental or health and safety issues. A detailed risk assessment will usually be required. 3.2 routine tests (Group 1 ) minimum tests required to monitor the liquid and to ensure that it is suitable for continued service Note 1 to entry: If the results obtained from these tests do not exceed recommended action limits, usually no further tests are considered necessary until the next regular period for inspection but, under certain perceived conditions, complementary tests may be deemed prudent. 3.3 complementary tests (Group 2) additional tests, which may be performed to obtain further specific information about the quality of the natural ester, and may be performed to assist in the evaluation of the natural ester for continued use in service 3.4 special investigative tests (Group 3) tests performed mainly to determine the suitability of the natural ester for the type of equipment in use and to ensure compliance with environmental and operational considerations 4 Categories of equipment In order to consider the different user requirements, equipment has been placed in various categories as shown in Table 1 . For practical and economic reasons, some electrical utilities may decide that their small transformers up to 1 MVA and 36 kV are not included in this classification. It is possible that routine monitoring programmes are not considered economical for this type of equipment.