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NSLS ESH Highlight #3

Lessons-learned from Electrical Shock "Near Miss"

Date: July 19, 1995 (Rev. 7/30/99)
Editor: W. Thomlinson, R. Casey

Large amounts of electrical power are used through out the NSLS complex, and electrical safety requires constant vigilance by everyone working on our floors. Electrical safety requirements have been established by the Laboratory and can be found in Standard 1.5.0 "Electrical Safety", Standard 1.5.1 "Lock-out/Tag-out Requirements", and 1.5.2 "Design Requirements for Electrical Equipment". Training is required for personnel involved in activities involving these issues.

Several years ago, we had a potentially lethal event occur when NSLS technical staff were working on the NSLS booster power supplies. While one technician was removing 480 volt power leads from one unit, the main power circuit breaker (previously determined to be in an off condition) was energized by a second individual. Fortunately the leads shorted to ground and the technician was not harmed. However, we were very fortunate that a serious injury did not occur under these circumstances.

Proper adherence to lock-out/tag-out procedures would have prevented this occurrence.

Many personnel work on equipment at the NSLS, and all of us probably

work on electrical systems at home. It is imperative for every individual to use common sense, and to adhere to the electrical safety requirements contained in the standards and discussed during training. This event serves as a lesson learned and a reminder-- electrical systems are dangerous and safe operating procedures must be followed.

Time pressure to complete a job must never enter into a decision regarding non-compliance with the requirements. We must work safely!