Y. Insulating Liquids and Gases

1. Properties and Types

Identify properties, types, and applications ^{2, 3, 4}

• ASTM D3487 Standard Specification for Mineral Insulating Oil Used in Electrical Apparatus ⁴
• Insulating Liquid Basics
• What is the best transformer coolant?
• Transformer Oil: Testing, Types & Properties
• Analyzing transformer insulating fluid
• Sulfur Hexafluoride Gas Hazards

2. Inspection and Test Procedures

Apply sampling procedures in accordance with ASTM ^{2, 3, 4}

Important EPA Standards

• 40 CFR Part 761 Protection of Environment
• 40 CFR 761.125 Requirements for PCB spill cleanup
• 40 CFR 761.3 Definitions
• Identification, Management, and Proper Disposal of PCB-Containing Electrical Equipment
• PCB Questions & Answers

Sampling Procedures

• ASTM D923 Standard Practices for Sampling Electrical Insulating Liquids ⁴
• NFPA 70B: Chapter 11.19 Insulating-Liquid Analysis ^2 3 4
• Specific Gravity of Transformer Oil, Where to Draw Your Sample
• Transformer Oil Sampling

Demonstrate understanding of ASTM dielectric breakdown tests ^{2, 3}

• ASTM D877 Standard Test Method for Dielectric Breakdown Voltage of Insulating Liquids Using Disk Electrodes
• How to Determine Dielectric Breakdown Voltage

Demonstrate understanding of ASTM moisture content, and purity tests ³

• ASTM Insulating Oil Test Methods
• Laboratory Testing of Natural Ester Dielectric Liquids
• Gassing Characteristics of Transformer Oil Under Thermal Stress
• Keep Your Transformer Working Like a Well-Oiled Machine

Employ methods and procedures for field testing of insulating oils and gases ⁴

• Reserved

3. Interpretation of Test Results

Evaluate results of ASTM tests ^{2, 3, 4}

Important Standards

• IEEE C57.104 Guide for the Interpretation of Gases Generated in Oil-Immersed Transformers ^3 4
• IEEE C57.106 Guide for Acceptance and Maintenance of Insulating Mineral Oil in Electrical Equipment ⁴
• IEEE C57.147 Guide for Acceptance and Maintenance of Natural Ester Insulating Liquid in Transformers ⁴
• IEEE C57.111 Guide for Acceptance of Silicone Insulating Fluid and Its Maintenance in Transformers
• IEEE C57.121 Guide for Acceptance and Maintenance of Less-Flammable Hydrocarbon Fluid in Transformers
• NETA-ATS 2017: Table 100.4 Insulating Fluid Limits ^2 3 4
• NETA-MTS 2019: Table 100.4 Insulating Fluid Limits ^2 3 4

DGA

• The Power of DGA in oil analysis
• Dissolved Gas Analysis of Transformer Oil
• Dissolved Gas Analysis and the Duval Triangle
• Dissolved Gas Analysis for Transformers
• Cause of Hydrogen Gas in Transformers
• Is Hydrogen Gas in Transformer Oil the Best Early Indicator of a Fault?
• The importance of measuring oxygen in DGA

Insulating Fluid Analysis

• Understanding Your Test Results
• Guide to insulating oil dielectric breakdown testing MEGGER Handbook
• A Guide to Transformer Oil Analysis
• Dissipation Factor, Power Factor, and Relative Permittivity of Insulating Oil
• Condition Assessment of Oil Circuit Breakers and Load Tap-Changers by the Use of Laboratory Testing and Diagnostics
• Understanding Water in Transformer Systems
• ASTM D445 – Standard Test Method for Kinematic Viscosity

Recommend corrective actions and remediation techniques ⁴

• What to do if transformer has an excessive moisture content

Last Update: Aug 21, 2023