Mark C. Ode

I received an email recently from a good friend requesting I write an article on knob-and-tube wiring. This request brought back memories of when I was an electrical contractor in the Phoenix area, licensed for 600V and lower...

Section 90.2(B)(5) states that the National Electrical Code does not apply to installations that are under the exclusive control of the electric utility company. Has anyone ever questioned the validity of this requirement...

When a homeowner ASKs an electrical contractor to add extra circuits and receptacles to an existing home, does the 2020 National Electrical Code permit them to be added to bathrooms, kitchens and garages? Adding new circuits...

Certain phrases are used so commonly in the electrical industry that an explanation seems to be almost unnecessary. However, the definition might not specifically be found within the National Electrical Code. One phrase that...

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...

I have noticed a disturbing trend over the past year. I feel a professional—and moral—responsibility to address what may be a dangerous installation of decorative backyard lighting. I totally understand that a person can...

Chapter 7 of the National Electrical Code includes many articles, such as Emergency Systems (Article 700); Legally Required Standby Systems (Article 701); Optional Standby Systems (Article 701); Class 1, 2, and 3 Remote...

I recently had a home security system installed. It was vastly different from the systems I have had in my other homes over the years. It is certainly much different than the residential and commercial systems I installed as...

Knob-and-tube wiring was used in buildings as a source of electrical energy from the 1880s. From the late 1930s–1950s, nonmetallic sheathed cable (type NM cable) and armored cable (type AC cable) were installed without an...

Requirements for the number and location of receptacles for dwelling unit kitchen countertops, islands and peninsulas changes with every National Electrical Code cycle. Many of these changes stem from architects’ and custom...

New and existing residences can benefit from the proper installation of outside lighting for security and adequate illumination. Although security is the primary requirement, the lighting must also be fashionable and...

Following up on my November 2020 article, here is further information on the ramifications of the change to the long-standing six disconnect rule in Section 230.71 of the National Electrical Code . Remember that this rule was...