Electrical Shock from Laser Power Supply

Key Instruction Points

  • Do not defeat machine safety interlocks.

  • Do not work around energized, exposed conductors.

A laboratory worker noticed condensation on the high voltage power supply for a high-powered laser. With the power still on, he wiped the moisture with a tissue, making contact with the exposed anode terminal at approximately 17,000 volts DC to ground.

He received a severe electrical shock and second degree burns to his right thumb and abdomen. Witnesses stated that they heard a loud "snap" and then heard the laboratory worker scream and stagger out to the hallway. He was immediately met by a secretary, and told her, "I got a shock," as he collapsed into her arms and onto the floor. He had no pulse and was not breathing. Public Safety officers were nearby and immediately started CPR. The ambulance crew arrived and was able to restore his heartbeat using a defibrillator.  

Fortunately, the laboratory worker lived to tell his story. He said that he knew that the power was on but was not aware that contact was possible at the high voltage terminals. The interlocks had been defeated and guards removed with no alternate guarding or precautions taken.  

Understand the operating characteristics of equipment before use. Do not defeat machine safety interlocks. Do not work around energized exposed conductors.