What Is the Order of Transformer Tests?
Quick answer — Transformer tests follow a sequence: first the electrical measurements (ratio, polarity, winding resistance, vector group), then the dielectric tests (insulation resistance, power factor, applied and induced voltage), then the performance tests (no-load and load loss, impedance) and finally the temperature-rise, impulse and short-circuit tests (type). Routine tests are run on every unit in this order, with type tests on the design.
What is the sequence of transformer tests?
Measurement
Turns ratio and polarity, vector group, winding resistance and the short-circuit impedance/leakage reactance are measured first.
Dielectric tests
Insulation resistance, power factor, the applied-voltage (between windings and earth) and induced-voltage (inter-turn) tests, and the impulse tests follow.
Performance and temperature
No-load and load losses, impedance, and the temperature-rise test on the design; then special tests by agreement.
References & standards
- IEC 60076-1
- IEEE C57.12.90
Related
Related manufacturers
Prolec GE (GE Vernova) · Prolec GE Waukesha · Hitachi Energy USA · Siemens Energy · Eaton · Virginia Transformer Corp
Related components
Technical content is prepared from engineering references, standards frameworks, manufacturer documentation and industry sources. Contractual or compliance decisions should refer to current official standards. TransformerPath Technical Editorial.
Source transformers for this application
Submit an RFQ or browse manufacturers and components.
Submit an RFQ Get Verified