Mark C. Ode

For example, has a limited amount of NM cable been installed in outside locations, such as inside a Type 3R enclosure or inside electrical metallic tubing (EMT) where the EMT has been installed exposed on an outside wall, and...

When I was an electrician, I tried to ensure the location and sequence of switches made sense, especially when there were several installed in one location. My goal was that homeowners could understand the installations and...

Switching out circuit breakers or fuses in existing homes Care must be taken when replacing circuit breakers and fuses in existing services and panelboards at single- family, two-family and multifamily dwellings. Older single...

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...

Periodically, a change in the National Electrical Code occurs that is long overdue, such as 2020‘s new Section 300.25. This change may have long-term consequences for electrical contractors, especially if the designer...

When I was doing fire and electrocution investigations, I received a phone call from an insurance company about a fire in a home the company insured. Upon arrival at the home, I discovered that the fire department had...

Every National Electrical Code cycle, from the advent of ground-fault circuit-interrupter (GFCI) protection in Section 680-4 in the 1968 NEC , has featured changes in the installation and application of GFCIs. The first GFCI...

Even though the 2020 National Electrical Code was just issued in September 2019 and many states will not adopt the new Code until this year, electrical contractors should be aware of the major changes that will affect most...

In the early 1950s, most 15- and 20-ampere receptacles in commercial buildings and residential dwelling units were ungrounded, two-prong receptacles supplied by branch circuits without an equipment grounding connection. In...

A few years ago, I received two phone calls regarding voltage gradients in swimming pools at existing homes in North Carolina. The pools had supposedly been installed using 680.26(A) and (B). This section of the Code was...

The 2020 edition of the National Electrical Code, issued Aug. 5, 2019, became effective Aug. 25, 2019, and superseded all 54 previous editions beginning in 1897.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...

Last month’s article covered the technical requirements of power over ethernet (PoE), limited-power (LP) cable, regular Class 2 and 3 cables and the temperature limitations of Class 2 and Class 3 cables and installations. But...