IEC 60422:2024 provides monitoring guidance and procedures that are required for the use and maintenance of mineral insulating oils and other hydrocarbon-based liquids in transformers and other electrical equipment, including strategic spares and tanks for holding spare parts and components. This document is applicable to mineral insulating oils, originally supplied conforming to IEC 60296, in transformers, switchgear and other electrical apparatus where oil sampling is reasonably practicable, and where the normal operating conditions specified in the equipment specifications apply. This document is also intended to assist the power equipment operator to evaluate the condition of the oil and maintain it in a serviceable condition. It also provides a common basis for the preparation of more specific and complete local codes of practice. The document includes recommendations on tests and evaluation procedures, and outlines methods for reconditioning and reclaiming oil, and the decontamination of oil contaminated with PCBs. NOTE\u2003The condition monitoring of electrical equipment, for example by analysis of dissolved gases, furanic compounds or other means, is outside the scope of this document.<\/p>\n
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| 2<\/td>\n | undefined <\/td>\n<\/tr>\n | ||||||
| 5<\/td>\n | Annex ZA (normative)Normative references to international publicationswith their corresponding European publications <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | English CONTENTS <\/td>\n<\/tr>\n | ||||||
| 10<\/td>\n | FOREWORD <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | INTRODUCTION <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 1 Scope 2 Normative references <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 3 Terms and definitions <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 4 Properties and deterioration or degradation of oil 5 Categories of equipment <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 6 Sampling of oil from equipment Tables Table 1 \u2013 Categories of equipment <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 7 In-service oil diagnostic tests 7.1 General Table 2 \u2013 Tests for in-service mineral insulating oils <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 7.2 Colour 7.3 Appearance 7.4 Breakdown voltage (BDV) <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 7.5 Water content 7.5.1 Water content in the oil and paper system 7.5.2 Influence of water on the solid and liquid dielectric system <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 7.5.3 Water in oil <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 7.5.4 Water in the solid insulation Figures Figure 1 \u2013 Water solubility curves for unused mineral oil as adapted from literature [5] (according to Formula (3)) <\/td>\n<\/tr>\n | ||||||
| 24<\/td>\n | 7.5.5 Interpretation of results <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 7.6 Acidity Figure 2 \u2013 Hysteresis loops of %RS vs. oil temperature in transformers with 3 different water content levels [5] <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 7.7 Dielectric dissipation factor (DDF) and resistivity Figure 3 \u2013 Correlation between resistivity and dissipation factor [6] <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | 7.8 Inhibitor content 7.8.1 Oxidation stability 7.8.2 Monitoring of uninhibited and inhibited oils 7.9 Sediment <\/td>\n<\/tr>\n | ||||||
| 28<\/td>\n | 7.10 Sludge 7.11 Interfacial tension (IFT) 7.12 Particles <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | 7.13 Flash point 7.14 Compatibility 7.14.1 General 7.14.2 Compatibility between different insulating mineral oils (miscibility) <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | 7.15 Pour point 7.16 Density <\/td>\n<\/tr>\n | ||||||
| 31<\/td>\n | 7.17 Viscosity 7.18 Polychlorinated biphenyls (PCBs) 7.19 Corrosive sulphur in mineral insulating oil 7.19.1 General <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | 7.19.2 Corrosive sulphur 7.19.3 Potentially corrosive sulphur 7.19.4 Dibenzyl disulphide (DBDS) <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | 7.20 Metal passivator 7.21 Air release and foaming 8 Evaluation of mineral insulating oil in new equipment <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | 9 Evaluation of oil in service 9.1 General Table 3 \u2013 Recommended limits for mineral insulating oils after filling in new electrical equipment prior to first energization at site <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | 9.2 Frequency of examination of oils in service <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | 9.3 Testing procedures 9.3.1 General 9.3.2 Field tests Table 4 \u2013 Recommended frequency of testing <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | 9.3.3 Laboratory tests 9.4 Classification of the condition of oils in service 9.4.1 General 9.4.2 Transformers 9.4.3 Tap-changers <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | 9.4.4 Instrument and protection transformers 9.4.5 Circuit breakers and switchgear 9.4.6 Oil filled and OIP bushings <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | 9.5 Corrective action <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | 10 Interpretation of results Table 5 \u2013 Transformers and reactors \u2013 Application and interpretation of tests <\/td>\n<\/tr>\n | ||||||
| 46<\/td>\n | Table 6 \u2013 Tap-changers \u2013 Application and interpretation of tests <\/td>\n<\/tr>\n | ||||||
| 47<\/td>\n | Table 7 \u2013 Instrument and protection transformers \u2013 Application and interpretation of tests <\/td>\n<\/tr>\n | ||||||
| 48<\/td>\n | Table 8 \u2013 Circuit breakers and switchgear \u2013 Application and interpretation of tests <\/td>\n<\/tr>\n | ||||||
| 49<\/td>\n | Table 9 \u2013 Oil filled and OIP bushings \u2013 Application and interpretation of tests <\/td>\n<\/tr>\n | ||||||
| 50<\/td>\n | 11 Handling and storage Table 10 \u2013 Summary of typical actions <\/td>\n<\/tr>\n | ||||||
| 51<\/td>\n | 12 Replacement of oil in electrical equipment 12.1 Replacement of oil in transformers with an Um below 72,5 kV and in switchgear and associated equipment 12.2 Replacement of oil in transformers with an Um of 72,5 kV and above <\/td>\n<\/tr>\n | ||||||
| 52<\/td>\n | 12.3 Replacement of oil in electrical equipment contaminated with PCBs 13 Addition of metal passivators to in-service oil 14 Treatment 14.1 Warning <\/td>\n<\/tr>\n | ||||||
| 53<\/td>\n | 14.2 Classification of treatment processes 14.2.1 General 14.2.2 Off-line (de-energized) vs on-line (energized) treatment <\/td>\n<\/tr>\n | ||||||
| 54<\/td>\n | 14.2.3 Batch vs continuous mode treatment 14.3 Reconditioning (degassing, drying and filtration) 14.3.1 General <\/td>\n<\/tr>\n | ||||||
| 55<\/td>\n | 14.3.2 Reconditioning equipment Table 11 \u2013 Conditions for processing mineral insulating oils (both inhibited and uninhibited) <\/td>\n<\/tr>\n | ||||||
| 56<\/td>\n | Table 12 \u2013 Beta ratio related to filter efficiency <\/td>\n<\/tr>\n | ||||||
| 57<\/td>\n | 14.3.3 Application to electrical equipment <\/td>\n<\/tr>\n | ||||||
| 58<\/td>\n | 14.4 Reclaiming 14.4.1 General <\/td>\n<\/tr>\n | ||||||
| 59<\/td>\n | 14.4.2 Reclaiming by percolation with single use sorbents 14.4.3 Reclaiming process using reactivating sorbents <\/td>\n<\/tr>\n | ||||||
| 61<\/td>\n | 14.4.4 Renewal of additives 14.5 Removal of PCBs using dehalogenation and related processes 14.5.1 General 14.5.2 Dehalogenation processes using sodium and lithium derivatives 14.5.3 Dehalogenation processes using polyethylene glycol and potassium hydroxide (KPEG) 14.5.4 Dehalogenation in continuous mode by closed circuit process <\/td>\n<\/tr>\n | ||||||
| 62<\/td>\n | 14.5.5 Corrosive sulphur removal using KPEG 14.6 Criteria for oil reclamation and treatments <\/td>\n<\/tr>\n | ||||||
| 63<\/td>\n | Annex A (normative) Criteria for reclamation and treatments A.1 General A.2 Key parameters to measure before and after reclamation Table A.1 \u2013 Parameters where limits should be agreed upon <\/td>\n<\/tr>\n | ||||||
| 64<\/td>\n | A.3 Addition of inhibitor after reclamation Table A.2 \u2013 Parameters where limits should not necessarily be set but should be measured for baseline and trending <\/td>\n<\/tr>\n | ||||||
| 65<\/td>\n | A.4 Time and location of sampling <\/td>\n<\/tr>\n | ||||||
| 66<\/td>\n | Annex B (informative) General guideline for moisture %RS for continuous online monitoring Table B.1 \u2013 Moisture %RS, continuous online monitoring, general guideline <\/td>\n<\/tr>\n | ||||||
| 67<\/td>\n | Annex C (informative) Normalizing water in oil for comparison and trending (historical practice) C.1 General C.2 Sampling temperature at or above 35 \u00b0C <\/td>\n<\/tr>\n | ||||||
| 68<\/td>\n | Figure C.1 \u2013 Normalization factors according to Formula (C.2) <\/td>\n<\/tr>\n | ||||||
| 69<\/td>\n | Annex D (informative) Material compatibility <\/td>\n<\/tr>\n | ||||||
| 71<\/td>\n | Annex E (informative) Test method for determination of sediment and sludge E.1 Sediment determination E.2 Sludge determination <\/td>\n<\/tr>\n | ||||||
| 72<\/td>\n | Annex F (informative) Contamination of oils with silicone <\/td>\n<\/tr>\n | ||||||
| 73<\/td>\n | Bibliography <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Mineral insulating oils in electrical equipment. Supervision and maintenance guidance<\/b><\/p>\n |