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Danger: Backfeed

Danger: Backfeed July 26th 1998: Detroit Michigan: A contract lineman with twenty years experience died yesterday from electrocution while making repairs to a single phase lateral. The circuit being worked on was one of many that incurred considerable damage when a wind storm blew through Western Wayne County on the evening of the 21st of July. The Circuit is a 4.8 kV delta containing solid banked secondary as well as ringed primary. The portion of the line being reconstructed was the first two spans of a single phase (2 phases) lateral. The primary was deadended three spans further into the lateral at a second transformer location. The secondary continued to the far side of the primary ring, where it was tied in with a third transformer fed from the the opposite side of the primary ring. The line crew had to replace both secondary and primary conductors from the T-buct to the first transformer location. The secondary was isolated by the crew at the next transformer location which was also where the primary deadended. Unfortunately the breaks in the secondary were placed so that the transformer was tied into the secondary feeding to the opposite side of the ring. The transformer was therefore backfed by the secondary feed from the opposite side of the ring. This energized the primary back to the work location. The primary side of the transformer at the location where the secondary break was cut in was not opened. This action (or inaction) coupled with the failure to test before touch led to a tragic incident which will stay with all those involved for the rest of our lives. Object lesson was to always take into consideration all possible sources of backfeed and/or treat as energized.