National Electrical Code (NEC) was first published in 1897 as a response by insurance underwriters to the numerous fires caused by early electrical systems. It is now updated and revised every three years with a new edition. If you can imagine how simple electrical systems were in 1897 compared to today, and add to that the fact that each revision is an overlay of the previous code, adding, deleting, and changing text here and there, how could it not get complicated? The photo above of the 1984 code on top of the 2017 code shows how much the NEC has grown in just the last 33 years.

    Also, the NEC is not intended for use by someone who is not a professional electrician. Electricians spend lots of hours studying the code for their licensing exam, then take continuing education courses regularly to keep up with the code changes. New technologies such as solar power and arc-fault breakers have to be integrated with code standards dating back 50 to 100 years, like the requirement for receptacle outlets to be grounded that was added in 1959. 

Learning To Speak A New Language:  Electrical Code

    A big part of learning the code is understanding the code-specific terminology. You have to acquire the nuances of “code speak." For examples, see our blog posts What is the difference between "grounded" and "grounding" electrical conductors? and What is the difference between a UL rating for dry, damp, and wet locations? and  What is the most important sentence to know in the entire National Electrical Code (NEC)? 

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Here’s links to a collection of our other blog posts about ELECTRICAL WIRING:

• Which house appliances need a dedicated electrical circuit?

• Can a short circuit cause a high electric bill?

• What is the maximum spacing requirement for securing NM-cable (nonmetallic-sheathed cable)?

• Is it alright to just put wire nuts on the end of unused or abandoned NM-cable or wiring?

• What causes copper wires to turn green or black in an electric panel?  

• What are typical aluminum service entrance wire/cable sizes for the electrical service to a house?

• Why is it unsafe to bond neutral and ground wiring at subpanels?

• Should I get a lightning rod system to protect my house?

• Why is a strain relief clamp necessary for the cord connection to some electric appliances?  

• Does a wire nut connection need to be wrapped with electrical tape?

• What is the minimum clearance of overhead electric service drop wires above a house roof?

• What are the requirements for NM-cables entering an electric panel box?

• What is the color code for NM cable (Romex®) sheathing?

• Why is undersize electric wiring in a house dangerous? 

• What causes flickering or blinking lights in a house?

• Why are old electrical components not always "grandfathered" as acceptable by home inspectors?

• How can I find out the size of the electric service to a house?

• What could cause an extremely high electric bill?

• Can old electrical wiring go bad inside a wall? 

• What is an open electrical splice?

• What are the most common electrical defects found in a home inspection? 

• What is the life expectancy of electrical wiring in a house? 

• What is an "open junction box"? 

• How dangerous is old electrical wiring? 

• What is a ground wire? 

• I heard that aluminum wiring is bad. How do you check for aluminum wiring? 

• What is "knob and tube" wiring? 

    Visit our ELECTRICAL page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.