According to the National Institute of Building Sciences (NIBS), Washington, D.C., construction companies comprise 13% of the global economy. And while the United States already plays a major leadership role in delivering...

Sometime between the 1925 and 1933 National Electrical Codes , the maximum number of service disconnects changed from one or two disconnects to a maximum of six. I cannot verify the exact edition where the change occurred. I...

Last month I wrote about a change in fiber optic standards that seemed out of step with the technical community. That raised questions such as how do fiber optic standards get written? And what are standards anyway...

How well do you understand the NFPA 72 requirements for pathway survivability? Like many other fire alarm applications, the code is not always clear, and there are quite a few different interpretations on this subject. Having...

The grounded conductor at the service provides two essential functions for the premises wiring system. The first is to serve as a current-carrying conductor for the load supplied. Second, it functions as the intentionally...

This Article focuses on revisions in Chapter 6 of the 2020 NEC, “Special Equipment,” and it includes the requirements for special equipment such as electric signs and outline lighting systems, electric vehicle (EV) supply...

Jim Dollard has an extensive background in codes and standards. If you have a query about the National Electrical Code (NEC) , Jim will help you solve it. Send questions to codefaqs@gmail.com. Answers are based on the 2020...

The 2020 edition of the National Electrical Code, issued Aug. 5, 2019, became effective Aug. 25, 2019, and superseded all 54 previous editions beginning in 1897. There were a total of 3,730 public inputs with 1,400 first...

Jim Dollard has an extensive background in codes and standards. If you have a query about the National Electrical Code (NEC) , Jim will help you solve it. Send questions to codefaqs@gmail.com. Answers are based on the 2017...

The purpose statement of the NEC, section 90.1(A) states, “The purpose of this Code is the practical safeguarding of persons and property from hazards arising from the use of electricity.” In other words, it all comes back to...

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...

Since moving south in June, I have paid a lot more attention to thunderstorms. Thunderstorms in the Southeast are more powerful and frequent than I experienced in the Northeast. The most severe thunderstorms generate...

Jim Dollard has an extensive background in codes and standards. If you have a query about the National Electrical Code, Jim will help you solve it. Send questions to codefaqs@gmail.com. Answers are based on the 2017 NEC...

Two recent headlines caught my attention. The first one is from June 29, 2019: “Fire breaks out in transformer at Providence power plant.” The report indicated that thick, black smoke caused a major traffic jam on Interstates...

For the past few national electrical code cycles, there has been a growing concern in the electrical industry with a phenomenon called electric shock drowning (ESD) occurring in and around marinas, boatyards, floating...

Jim Dollard has an extensive background in codes and standards. If you have a query about the National Electrical Code (NEC), Jim will help you solve it. Send questions to codefaqs@gmail.com. Answers are based on the 2017 NEC...

According to the 2018 edition of NFPA 70E, the definition of electrical safety is “identifying hazards associated with the use of electrical energy and taking precautions to reduce the risk associated with those hazards.”...

Jim Dollard has an extensive background in codes and standards. If you have a query about the National Electrical Code (NEC), Jim will help you solve it. Send questions to codefaqs@gmail.com. Answers are based on the 2017 NEC...