Correct and thorough pre-startup (SAT) testing is crucial due to the significant material value of transformers and the high costs associated with defects. Arya Transfo emphasizes the importance of conducting pre-startup tests and detailed analysis of the results by experienced experts using accurate and calibrated equipment before putting the transformer into operation. The following types of SAT tests can be performed on-site:

• Starting the motor drive and performing necessary controls on the OLTC
• Transformer vector group check, ratio measurement, and recording of magnetization current in all taps
• Measuring the ohmic resistance of windings in all phases and taps
• Measuring insulation resistance of coils to each other and to ground
• Insulation resistance measurement of the core, frame, and transformer body if accessible
• Capacitance and delta tangent measurement of capacitive bushings
• Measuring capacitance of windings relative to each other and to ground, and measuring insulation loss coefficient (Tan δ)
• Checking transformer protection signals and ensuring correctness of fan control circuit based on control panel map
• Measuring ratio and ohmic resistance, and checking polarity of CTs installed on the transformer
• Various tests on transformer oil, including testing for dissolved gases

Arya Transfo’s after-sales service company utilizes state-of-the-art measuring devices according to international standards to conduct pre-startup tests, complete checklists, and analyze results. In case of any defects in transformer performance, the company is prepared to cooperate by conducting various diagnostic tests to identify and rectify the issue.