Mark C. Ode

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...

Take care when replacing circuit breakers and fuses in existing services and panelboards at single-, two- and multifamily homes. Older single- and two-family homes with 100A to 200A, 120/240V single-phase services were...

New Section 680.4 in Article 680 in the 2020 National Electrical Code enables the authority having jurisdiction (AHJ) to require periodic inspection and testing of swimming pools, fountains and similar installations such as...

homes’ electrical systems require regular maintenance. Many homeowners do not realize that various parts of their system must be routinely exercised, examined for functional capability and tested, especially during the first...

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...

A friend called me recently with some intriguing questions about some electrical work that he was having done at his newly purchased home. The home was built in the mid-to-late 1950s with some electrical work done in various...

My single-speed swimming pool pump motor, installed in 2004, finally quit working. I nursed it along for many years and probably should have replaced it a long time ago. However, I kept finding other ways to spend the money...

July’s article provided a preliminary discussion on cathodic action and dissimilar metal reaction with deterioration of various metals, such as steel water and gas lines. Many of the old metal underground natural gas lines...

Cathodic action and dissimilar metal interaction are phenomena with a long history of recognition in the laws of physics as well as within the National Electrical Code. I first ran across this issue back in the 1970s and ‘80s...

An electrical contractor emailed me a photo of a feed-through all-in-one 200A 120/240V, single-phase, eight-circuit panelboard with 200A main circuit breaker. It had an auxiliary 2-pole circuit breaker position where up to a...

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...