Emerging modern technologies and ever-changing demands compete with each other to bring new changes to the sociotechnical life of human beings. OLTC is one such equipment connected as an integral part of the transformer to change the turns ratio while the transformer is in energized condition, to adjust the output voltage. Changing times and technology brought many changes in the OLTC techniques, design and operation. Traditionally OLTC is a complex mechanical device, which has some deficiencies. OLTC design elements are checked during the transition resistor test. Thus, OLTC testing for transition resistors is a method to enhance the reliability of OLTC design. This paper discusses a typical failure case of OLTC during the transition resistor test conducted in CPRI.
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