IEC 60567:2023

Overview

IEC 60567:2023 - "Oil-filled electrical equipment - Sampling of free gases and analysis of free and dissolved gases in mineral oils and other insulating liquids - Guidance" provides guidance on safe, repeatable techniques for sampling and analysing gases related to oil-filled electrical equipment. The standard focuses on sampling free gases from gas-collecting (Buchholz) relays and on methods to extract and quantitatively analyse dissolved gases in insulating liquids (DGA - dissolved gas analysis) using gas chromatography.

Key Topics

• Scope and exclusions
  • Covers sampling of free gases from gas-collecting relays and extraction/analysis of gases dissolved in oil and other insulating liquids.
  • Note: sampling of bulk oil from equipment (transformers, reactors, bushings, cables, capacitors) is covered by IEC 60475:2022.
• Sampling free gases
  • Describes three sampling methods for gases trapped in Buchholz relays: sampling by syringe, by oil displacement, and by vacuum. Free gases are analysed without preliminary treatment.
• Extraction of dissolved gases
  • Details three principal extraction techniques to transfer dissolved gases from oil to a gas phase:
    • Vacuum extraction (Toepler multi-cycle and partial degassing methods)
    • Stripping (bubbling carrier gas through the oil)
    • Headspace (partitioning between oil and a small gas volume)
• Gas analysis
  • Quantitative analysis of extracted gases by gas chromatography is specified, including apparatus, columns, detectors and calibration requirements.
• Standards for quality and reporting
  • Guidance on sample labelling, transfer, preparation of gas-in-oil standards, calibration, limits of detection and quantification, repeatability, reproducibility and reporting of results.
• Applicability to other insulating liquids
  • Annexes include provisions for ester and silicone-based insulating liquids and mercury-free or alternative extraction methods.

Applications

IEC 60567:2023 is essential for:

• Transformer and oil-filled equipment manufacturers implementing DGA programs.
• Utility asset managers and maintenance engineers performing condition monitoring and fault diagnosis.
• Independent test laboratories and diagnostic service providers performing DGA by gas chromatography.
• Safety and quality assurance teams establishing sampling procedures, calibration protocols and reporting formats.

Practical benefits include improved fault detection in power transformers, consistent sampling practice for Buchholz relays, and reliable quantitative DGA results used for condition assessment and maintenance planning.

Related Standards

• IEC 60475:2022 - Sampling of oil from oil-filled equipment (referenced for oil-sampling procedures).
• Consult other IEC and national standards on transformer diagnostics and DGA practice for complementary requirements and interpretation guidance.