Codes & Standards

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...

Some of the most challenging electrical installations involve healthcare. From major hospitals to clinics in pharmacies, anyone who is not intimately familiar with the intricacies of medical headwalls, major electrical...

Recently, I was asked to explain the reason for the ferrous metal raceway bonding requirements in 250.64(E). Although the National Electrical Code never uses the term “choke effect,” many in...

The last twenty years of the 20th century were filled with excitement and anticipation about what would happen in the century ahead. It would not be a normal change because...

To understand the purpose of ground-detection equipment installed for ungrounded systems, it is best to have a fundamental understanding of ungrounded system performance and the rules that apply to them...