The Mike Holt Podcast

Emergency System, Classification [700.2]

For most of us, a loss of utility or normal electrical power is an inconvenience and is usually restored as soon as humanly possible. But where electrical power is essential for maintaining safety to human life, an emergency electrical system is required. Do you know what types of occupancies might require this consideration and who classifies these systems as emergency? To answer these questions and fully understand what distinguishes an ‘Emergency System’ from a ‘Backup System, read the attached text (paying particular attention the ‘Informational Note’) and listen to the podcast as me and a panel of experts explain.

Emergency Disconnects [230.85, 2020 NEC]

For years, a common practice for one and two-family dwellings has been to install a meter enclosure outside and main breaker panel suitable for use as a service disconnect inside. As electrical professionals, many of us had that hunch to ask ourselves, "what about first responders." A recently added Code rule now requires an emergency disconnect for ALL one and two-family dwellings regardless of the panel's location indoors.

But what are the requirements of this new rule? Can the service disconnect act as an emergency disconnect, or does the emergency disconnect have to installed separately? How do we identify and distinguish between a service disconnect and an emergency disconnect?

Electric Vehicle Power Transfer System [625.1]

Electric vehicles have been around for a long time. With bi-directional transfer of electrical power from your electric vehicle to your home becoming commonplace, the industry has had to adapt and the scope of Article 625 has changed again. Listen to this podcast to learn the scope of what’s covered in this article and what has changed since the last cycle.

EGC for Parallel Conductors, Sizing [250.122(F), 2020 NEC]

250.122(F) EGC for Parallel Conductors, Sizing – https://www.MikeHolt.com/bonding. One of the costliest mistakes made in electrical installations is a failure to read and fully understand the Code rules for sizing and installing the EGC when paralleling conductors. Read your Code book while listening to this podcast and you could wind up saving yourself a huge amount of aggravation and money!

Conductor Jamming—Chapter 9, Table 1, Note 2 [2020 NEC]

When three conductors are pulled into a raceway, they may flatten out creating a condition where the conductors could jam. In this podcast we’ll explain how to avoid this condition.

Conductor Insulation [310.4, 2020 NEC]

Factors that impact conductor sizing include not only conductor ampacity and equipment terminal temperature rating, but also the conductor insulation temperature rating. In this podcast we discuss Table 310.4(A) which provides information on conductor insulation properties such as letter type, maximum operating temperature, application, insulation, and outer cover properties.

Class 1, Class 2, and Class 3 Remote-Control, Signaling, and Power-Limited Circuits, Scope [725.

To understand when to apply the requirements of Article 725 for remote-control and signaling circuits, you need to understand the Scope of this article. Listen to this podcast and discover what distinguishes “Class 1” from “Class 2” and “Class 3” circuits and what this article applies to.

Branch Circuit, Multiwire [210.4, 2020 NEC]

210.4 Branch Circuit, Multiwire – https://www.MikeHolt.com/code. Multiwire branch circuits are an efficient and cost-effective approach to installing electrical circuits, but there are inherent hazards when this wiring method is used. In this podcast, we discuss how important it is for these circuits to be installed and serviced properly, and the consequences for failing to do so!

Bonding, Radio Antenna Grounding [810.21, 2020 NEC]

810.21 Bonding, Radio Antenna Grounding – https://www.MikeHolt.com/bonding. You may be surprised at the number of CB and HAM radio operators there are around the country. These radio frequencies require line-of-sight antenna which requires a substantial height (some are hundreds of feet tall) to maintain that line-of-sight. You can probably already figure out that these heights make them a prime target for lightning strikes. Watch this video clip to help you comply with the Code rules for grounding these antennae.

Bonding, Other Enclosures [250.96, 2020 NEC]

250.96 Bonding, Other Enclosures – https://www.MikeHolt.com/bonding. If you remember that the whole purpose of bonding is to establish an “effective ground-fault current path” in order to clear a fault, then you can better understand why proper bonding of enclosures and raceways is crucial in maintaining a safe electrical installation.