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Tests and Analyses of Transformers and Transformer Circuit Breakers
Tests and analyses of power transformers and breakers: oil tests, insulation measurements, relay examination and cell tests in measurement-based reports.
Tests and analyses of transformers and transformer circuit breakers evaluate, numerically, the oil/dry transformers and their breaker-disconnector-protection gear converting voltage and switching energy safely in the plant: electrical measurement, chemical testing of insulating oil and mechanical examination are the tools. The aim is to catch insulation ageing, internal thermal damage or mechanical drift through data before a fault occurs, and to build the maintenance plan on that data. The detailed items are defined on our sub-pages such as the Insulation Oil Test, Dielectric Strength Test, Buchholz Relay Examination, Insulation Test, Transformer Earthing Measurement and Cell Insulation Test.
Why Measurement-Based Analysis?
Visual examination only reveals surface findings. The polymerisation degree of insulation paper, moisture and dissolved gases in oil, and the rise of contact resistance at joints become visible only through laboratory and field measurement. The main test sets in this group are:
- Oil analysis: Dielectric breakdown (basis), moisture (Karl Fischer), acidity (titration), dissolved gas analysis (DGA), refractive index and density — detailed in our Density Test and Acidity Test items.
- Electrical measurement: Winding resistance, leakage and insulation resistance (PI/DAR), loss factor (tan delta), ratio and vector group verification.
- Mechanical-gas: Buchholz relay, sudden pressure valve, level gauge, thermometer and fan-pump examination — Thermometer Examination and Oil Level Leak Inspection sit here.
Standards and Legal Basis
Tests run per the TS EN 60076 series (power transformer tests), TS EN 60422 / IEC 60422 (in-service supervision of oil-filled equipment), IEC 60567 (DGA guide) and, for oil test methods, TS EN ISO 1524 / IEC 60156. The legal base is Law No. 6331 with the Regulation on High Current Electrical Installations; the facility operator must perform periodic control, maintenance and measurement and document the results. Measurements are made by authorised electrical engineers; the instruments used (megger, DGA sampling pump, breakdown voltage set) carry calibration traceability.
Test Programme and Outcome
The transformer test programme is risk-based: full reference measurement (baseline) at commissioning, core oil-electric tests every 1-2 years in operation, shortening of DGA to 6-12 months on critical units. Results are assessed against historical measurements — not a single value but the rate of change drives the decision: a falling PI, rising moisture or climbing hydrogen concentration is a maintenance input. The report presents the assessment, findings and rectification proposals; the planned shutdown window and material suggestions tie to it. To receive an inventory and programme quotation for this set in our Tests and Analyses group, reach our team via the contact page.
FAQ on Transformer & Circuit Breaker Tests and Analyses
Diagnostic tests and analyses of power and distribution transformers with transformer circuit breakers (breaker, disconnector): insulation oil tests (dielectric strength, dissolved water, density, acidity, dissolved gas-DGA, particles), electrical tests (insulation resistance, fixed-moving contact resistance, tightness-torque, terminal-bushing control), Buchholz relay examination, thermometer verification, battery-rectifier control, cell in-out and insulation tests plus earthing measurement and general cleaning-maintenance. The aim is to catch the fault before it happens.
Periodic inspection documents conformity; analysis produces trend. Transformer oil carries the gas fingerprints of internal partial discharge, overheating and arcing (H2, CH4, C2H2, C2H4) and degradation products; dissolved water and acidity show the ageing of insulation paper and oil. Tracked as a time series, the degradation rate is readable even while inside limits. Thus the maintenance-repair-replacement decision is made planned instead of after a fault and production stop; the asset is protected.
The practical minimum for a routine oil sample and basic electrical tests is generally yearly; six months on critical or aged transformers. Dissolved gas analysis (DGA) is always repeated after a fault, relay trip, overload or abnormal operation. This IEC 60599 and TS EN 60076 referenced regime ties results to a reference baseline to read the trend. Cell-breaker tests and earthing measurement are planned coordinated with the periodic inspection calendar.
Every test is reported per equipment with the measurement value, the relevant limit-standard reference and a normal-caution-urgent class; where there is a finding, a root cause and a corrective action suggestion (oil change, drying-vacuum, tap-bushing maintenance, contact grinding, part replacement) is added. For DGA the Duval-Rogers triangle, for water-acidity the drying thresholds are used. First-year values become the comparison baseline of later analyses; the report is kept in the OHS-energy-insurance file.