If you're looking for a quick read on electronics-based electrical safety devices, check out “Overcurrents and Undercurrents — All about GFCIs, AFCIs, and Similar Devices,” written by Earl W. Roberts. The small-sized book, published in 2004 by Reptec, Mystic, Conn., begins with a discussion of the basics of shock and its effect on the human body, and moves into a review of overcurrent protection devices and grounding practices currently employed in the industry.

After introducing readers to the different types of residual current devices (RCDs) used in other parts of the world, the author does a good job of defining and describing all the different types of RCDs used in the United States, starting with the birth of the GFCI in 1961. He does a wonderful job of tying these different stages of product development in with the introduction of new NEC requirements, starting with the 1968 issue of the NEC. His Code revision sections offer a historical overview of how the requirements for these “people protectors” have progressed throughout the years. In addition, his descriptions of the various types of protective devices (GFCI, GFP, AFCI) are well supported with useful diagrams and photos.

The book also introduces us to several not-so-common devices in use today. Do you know what an ALCI does? What about an ELCI? Better yet, what do you know about IDCIs or LMRs? If these acronyms sound like Greek, maybe now is the time for you to check out this handy little reference tool.

The book lists for $25 and can be purchased from the author at reptec1@aol.com.