Transformer Oil Analysis

Transformer Oil Testing and Analysis

Assess insulation condition. Identify warning signs. Plan maintenance with confidence.

Environmental Testing and Laboratories Company (ETLCO) provides transformer oil testing to support utilities, industrial facilities, maintenance contractors, and operators of oil-filled electrical equipment across Saudi Arabia.

Our Oil & Gas Laboratory helps clients assess insulating oil condition, investigate potential faults, and obtain data for maintenance planning. From routine monitoring to targeted investigations, we tailor the testing scope to the oil type, equipment, operating history, and applicable specifications.

Why Test Transformer Oil?

Transformer oil serves as an electrical insulating medium and helps transfer heat away from internal components. Changes in its condition can provide valuable information about oil deterioration, contamination, and developing equipment problems.

Transformer oil analysis supports:

• Condition monitoring: Track changes in oil properties and insulation condition over time.

• Fault investigation: Assess indicators that may be associated with thermal or electrical faults.

• Maintenance planning: Provide evidence for decisions about further inspection, oil treatment, or replacement.

• Quality verification: Check new or replacement oil against agreed specifications before use.

• Compliance documentation: Support applicable technical, contractual, and regulatory requirements.

Results are most useful when considered alongside previous test data, equipment loading, maintenance records, and manufacturer guidance.

Our Transformer Oil Testing Capabilities

ETLCO offers a range of tests for assessing the electrical, chemical, and physical properties of transformer oil. The testing program is selected according to the insulating fluid and the purpose of the assessment.

Dissolved Gas Analysis — DGA

Dissolved gas analysis measures gases present in transformer oil. Gas patterns, concentrations, and changes over time can help identify conditions associated with overheating, partial discharge, or electrical arcing.

DGA supports fault investigation and condition monitoring when interpreted alongside equipment history and other diagnostic findings.

Dielectric Breakdown Voltage

This test evaluates the oil’s ability to withstand electrical stress under specified test conditions. It helps assess insulating quality and can indicate the influence of contaminants such as moisture or particles.

Dielectric Dissipation Factor

Also known as the dissipation factor or tan delta test, this analysis assesses dielectric losses in the oil. Changes in results can help indicate contamination or deterioration affecting its electrical properties.

Specific Resistance — Resistivity

Resistivity testing measures the oil’s resistance to electrical conduction. It complements other electrical tests when assessing insulating oil quality and the potential presence of conductive contaminants.

Water Content

Moisture analysis helps assess an important factor affecting insulating performance. Results should be evaluated with consideration for the oil type, sampling temperature, and the relationship between moisture in the oil and solid insulation.

Acid Number

Acid number testing measures acidic constituents in the oil. Tracking changes can help assess oil ageing and support decisions about further investigation or maintenance.

Interfacial Tension

Interfacial tension testing helps assess changes associated with polar contaminants and oil degradation products. It is commonly considered alongside acidity and other oil condition indicators.

Furans by HPLC

Furan analysis using high-performance liquid chromatography (HPLC) measures compounds that can be associated with the degradation of cellulose insulation.

Results can support an assessment of paper insulation ageing, with interpretation informed by equipment design, oil treatment or replacement history, and other operating information.

Oxidation Stability

Oxidation stability testing evaluates the oil’s resistance to oxidation under specified conditions. It supports assessment against relevant product requirements.

Oxidation Inhibitor Content — DBPC

DBPC testing measures the concentration of a commonly used oxidation inhibitor in inhibited insulating oils. It helps assess inhibitor levels against the relevant oil specification or maintenance requirements.

Copper Corrosion and Sulfur-Related Testing

Copper corrosion and applicable sulfur tests help assess characteristics relevant to the interaction between oil and equipment materials. The testing scope is selected according to whether the objective is to measure sulfur content or investigate potentially corrosive sulfur compounds.

Physical Properties and Handling Characteristics

Additional testing capabilities include:

• Density: To support oil characterization and product consistency checks.

• Colour: To document appearance and changes that may warrant further investigation.

• Kinematic viscosity: To assess flow properties relevant to oil circulation and heat transfer.

• Pour point: To evaluate low-temperature flow characteristics.

• Flash and fire points: To assess relevant properties under specified test conditions.

• Rust prevention characteristics: Where applicable to the oil specification and agreed test method.

Additional parameters can be discussed with our laboratory team based on the equipment and testing objectives.

Testing Support Throughout the Equipment Lifecycle

New Oil Acceptance

Verify the quality of new or replacement insulating oil before filling or topping up equipment, using a scope matched to the product specification.

Routine Condition Monitoring

Establish baseline results and monitor changes through periodic sampling. Consistent sampling practices and historical data make it easier to identify trends requiring attention.

Investigation of Abnormal Conditions

Use targeted testing following unusual operating observations, alarms, or changes in previous results. Laboratory findings help inform the next stage of technical investigation.

Assessment Before and After Oil Treatment

Compare selected properties before and after filtration, drying, or other oil treatment to evaluate changes in the measured parameters.

Maintenance and Asset Planning

Use oil analysis alongside inspections and other equipment diagnostics to prioritize maintenance and support asset management decisions.