Case Study
A company was contracted to install wiring and fixtures in a new office complex. The third floor was being prepared in a hurry for a new tenant, and daily changes to the electrical system blueprints were arriving by fax. The light fixtures in the office were mounted in a metal grid that was fastened to the ceiling and properly grounded.
A 23-year-old man apprentice electrician was working on a light fixture when he contacted an energized conductor. He came down from the fiberglass ladder and collapsed. Apparently, he had contacted the "hot" conductor while also in contact with the metal grid. Current passed through his body and into the grounded grid. Current always takes a path to the ground. In this case, the worker was part of that path.
He was dead on arrival at a nearby hospital. Later, an investigation showed the victim had cross-wired the conductors in the fixture by mistake. This incorrect wiring allowed electricity to flow from the live circuit on the completed section of the building to the circuit on which the victim was working.
Below are some safety procedures that should have been followed in this case. Because they were ignored, the job ended in death.
- Before work begins, all circuits in the immediate work area must be shut off, locked out, and tagged out- then tested to confirm they are de-energized.
- Wiring done by apprentice electricians should be checked by a journeyman.
- Supervisors should always review changes to an original blueprint in order to identify any new hazards the changes might create.
Knowledge Check Choose the best answer for the question.
8-4. Wiring done by apprentice electricians should _____.
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