In-service reclassification of askarel transformers-Application criteria and field results

Until recently, industry could not offer a means to clean an askarel (pure polychlorinated biphenyl (PCB)) transformer so that it could be reclassified to non-PCB status for continued use. There are now several field-proven processes by which askarel transformers may be reconditioned with guaranteed reclassification to non-PCB status of less than 50 PPM. One particular procedure by which commercially owned transformers have been reclassified at very low PCB levels, following a few months of processing and ninety days of in-service waiting period required by EPA (US Environmental Protection Agency) regulations 40 CFR 761, is discussed. A PCB reconditioning process was introduced in early 1986 that has already resulted in more than 60 commercial transformer reclassifications. Over two years of successful non-PCB history of specific transformers is traced. The process, extensive test program, and actual case history results are reported