The SFRA test is Non-intrusive (non-destructive) test. SFRA is an OFF line testing and it can be carried out for any voltage rating of Power Transformer, Generator Transformer and Distribution Transformer.
The measurement of SFRA can be a part of regular transformer maintenance. The SFR Analyzer identifies the following abnormalities in the transformer before they lead to failure,
- Core movement.
- Winding deformation and displacement.
- Faulty Core ground.
- Partial winding collaspe.
- Hoop buckling.
- Broken or loosened clamping structures.
- Shorted turns and open winding.
The Technique of SFRA is a major advance in transformer condition monitoring analysis. This is a proven technique for making accurate and repeatable measurements.
The test can be carried out,
- First to obtain initial signature (record) of the transformer Swwep frequency response for further reference/comparison.
- Periodical measurement as a maintenance check, once in two years.
- Immediately after a major external Short Circuit, specially for faults electrically closer to transformer.
- Transportation or re-location of transformer.
- Earthquakes.
- Pre-commissiong check.