Engineering Controls

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Engineering Controls

Engineering controls are devices that isolate the worker from the hazard of exposure. In the realm of electrical safety, engineering controls include such devices as:
  • A light switch or outlet cover plate
  • A door on a breaker panel
  • Covers over terminal posts
  • Ground pin on an electric plug (Three-prong plug)
  • Ground fault circuit interrupters (GFCI), particularly in damp or wet locations
A GFCI is a fast-acting circuit breaker designed to shut off electric power in the event of a ground fault within as little as 1/40 of a second. It works by comparing the amount of current going to and returning from equipment along the circuit conductors. When the amount going differs from the amount returning by approximately 5 milliamperes, the GFCI interrupts the current. The arrow in the image on the right points to a GFCI that is incorporated into the receptacle outlet.