"Retrofilling"-A Technique to Polychlorinated Biphenyls (PCBs)

Mineral oil-filled transformers containing 500 ppm PCBs or greater are classified by the Environmental Protection Agency (EPA) as PCB transformers. As such, these transformers are not allowed by EPA regulations to be rebuilt or internally serviced. By lowering the contamination level of PCBs below 500 ppm, the useful service life of these transformers may be extended since they would be reclassified as PCB-contaminated or non-PCB transformers, and internal servicing would be allowed. One means for accomplishing this reduction is retrofilling. The results of this study have been tabulated and guidelines have been specified to determine the suitability of a transformer to be retrofilled. This study reflects the effectiveness of retrofilling transformers to achieve reclassification