The electrical industry is based around one concept and that is, control. More importantly, it is based upon the safe control of the flow of electrons through a conductive object. By controlling electricity we are able to make the electricity perform work that improves our lives. Electricity can be employed to do anything from simple tasks like lighting our homes and cooking our foods to more complex tasks like cell phones and powering the International Space Station. For all the wonderful and amazing things that electricity can do to make our lives better and more interesting, there is also a dangerous and deadly side to it as well. Common electrical hazards include shock, arc flash/blast, and fire. These are all unfortunate side effects that arise when electricity is not properly controlled.
A fundamental part of properly controlling electricity is having the correct size conductors. The National Electrical Code contains requirements for sizing and protecting conductors that, when correctly followed and maintained, will result in an installation that is essentially free from electrical hazards. The purpose of the NEC is after all, the "practical safeguarding of persons and property from hazards arising from the use of electricity," as found in section 90.1. Properly sized conductors reduce these hazards by providing ample current carrying capacity to supply the desired load.
This series of short blogs and discussions will be aimed at dissecting the NEC requirements for properly sizing conductors in various situations, as well as properly protecting these conductors from overcurrent. Stay tuned over the course of the next few weeks to be a part of this discussion as we explore the most fundamentally important skill in the electrical industry.
Until next time,