The National Electrical Code (NEC)is published every 3 years by the National Fire Protection Association. It is offered as the minimum safety standard for electrical installations, but is not a law until adopted by the respective state or municipal governing body. The 1999 NEC has undergone some major revisions since the 1996 edition in order to improve the readability and understandability of a document which is not written in lay-mans terms. The NEC states that it does not intend to provide a design specification nor an instruction manual for the untrained. This re-write has been successful in helping to clarify and improve many areas, particular Article 250 on Grounding. Many exceptions have been removed from the 1996 version and re-written into a "positive" text in the 1999 edition, helping to reduce some of the confusion. The larger format of the 1999 NEC makes it easier reading, and makes the tables much more usable.
Certainly, additional study and supplemental references are essential in order to fully comprehend the meaning of the NEC and the intended application in our every day wiring installations. As a certified electrical instructor and licensed electrial inspector, I use the NEC every day and have found that the 1999 edition is an improvement over the 1996 edition.