Jim Dollard has an extensive background in codes and standards. Send questions about the National Electrical Code (NEC) to Jim at codefaqs@gmail.com. Answers are based on the 2020 NEC. RVs as dwelling units Do the new rules...

Jim Dollard has an extensive background in codes and standards. Send questions about the National Electrical Code (NEC) to Jim at codefaqs@gmail.com. Answers are based on the 2020 NEC. GFCIs in elevator pits During an...

If a large quantity of current-carrying conductors is installed in a raceway outside in an ambient temperature that can reach 125°F, what are the Code requirements regarding applied ampacities? These conductors supply...

I was recently asked an interesting question involving parallel copper, aluminum and copper-clad aluminum conductors installed in parallel. The question was about 310.10(G), and whether cables installed in parallel must be...

Jim Dollard has an extensive background in codes and standards. Send questions about the National Electrical Code (NEC) to Jim at codefaqs@gmail.com. Answers are based on the 2020 NEC. Service conductors Does the NEC permit...

Splices and taps of conductors have been in the National Electrical Code for a long time. The 2020 NEC contains major changes involving distribution blocks, splices and taps, and to understand the reasons for these changes...

With the addition of new Section 725.144 and the accompanying Table 725.144 in the 2017 NEC covering transmission of power and data to a powered device comes the requirement for a special marking of the cable used for these...

A very knowledgeable electrical contractor in the Phoenix area recently emailed me, stating he was having a National Electrical Code (NEC) discussion with a local electrical inspector. The discussion involved the sizing of...

I have always been fascinated by cables and conductors—sometimes referred to as wires in the National Electrical Code (NEC) and other standards—and the insulation for these cables and conductors, as well as their multiple...

If you have a problem related to the National Electrical Code (NEC), are experiencing difficulty in understanding a Code requirement, or are wondering why or if such a requirement exists, ask Charlie, and he will let the Code...