How do you develop a safe, flexible, reliable electrical power distribution system? What are some of the fundamental rules?
One good place to start is the National Electrical Code (NEC). This important book is not intended to be a design specification, nor instruction manual for use by untrained personnel, but it does have a wealth of information covering generally accepted procedures applicable to most situations. The first code was developed in 1897 as the result of the united efforts of various insurance, electrical, architectural and allied interests. It is revised on a three-year cycle. Each new edition becomes effective when issued.
The NEC has been adopted as a local standard by many authorities and its provisions have the force of law in many situations (90-4). However, its articles have two different degrees of force: Any rule using the word "shall" must be obeyed, but the phrase "shall be permitted" allows some leeway in carrying out that provision. "Shall" indicates it is a mandatory requirement. "Fine print notes" (FPN) are like footnotes. They are used to explain some point in an article.
