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March-April 2013
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* Voltage Thresholds in the NEC. Moving on up?

by Jim Dollard

There were 120 proposals submitted to raise the 600-volt threshold in the NEC to 1000-volts in the 2014 NEC cycle. These proposals were submitted by the High Voltage Task Group (HVTG), which was appointed by the NEC Correlating Committee. The HVTG was charged to review all NEC requirements and/or the lack of requirements for circuits and systems operating at over 600-volts. Read more

Perspectives on PV

* Batteries in PV Systems

by John Wiles

Electrical power outages are becoming more common in recent times with man-made and natural disasters, and the aging utility infrastructure. With natural disasters such as Hurricane Sandy, tornadoes, and other severe weather conditions, many people who are already using photovoltaic (PV) systems and many that do not have PV systems are going to be interested in utilizing PV systems in the event of electrical power outages. The electrical inspector can expect to see increasing numbers of battery-backed-up, utility-interactive photovoltaic power systems. Read more

* Article 240, Part 2 — Overcurrent Protection

by Randy Hunter

In Part One of Article 240, we left off with a basic review of circuit protection. Now that we have an understanding of how it operates, let’s get back to Part II of Article 240 which starts at 240.21 Location in Circuit. Here we find a very simple statement which requires the overcurrent protection to be located at the point where ungrounded conductors receive their supply. As simple as this is, we naturally have exceptions which will allow taps to be made under certain conditions. For this section, a tap is a conductor which is connected to a system; however, it is not sized to handle the ampacity of the upstream overcurrent protective device. We will cover the limited allowable conditions. Read more

* SPE-1000 0151 — Model Code for the Field Evaluation of Electrical Equipment

by Steve Douglas

The fourth edition of the SPE-1000 Model Code for the Field Evaluation of Electrical Equipment (SPE-1000) is scheduled to be published by June of this year. The SPE-1000 was first published in 1994 providing requirements used by inspection bodies accredited by the Standards Council of Canada when field evaluating unapproved electrical equipment. Used in conjunction with the requirements of the Canadian Electrical Code (CE Code), Part I, the SPE-1000 document provides construction requirements for the equipment being evaluated along with testing criteria, and minimum marking for equipment nameplates, warning and caution notices. Read more

Shock and Awe

by Thomas A. Domitrovich

Recognizing shock hazards can be difficult to the untrained or inexperienced eye on job sites and especially areas / facilities that have experienced storm damage. An electrocution is the result of coming in contact with a lethal amount current. Shock protection comes in many forms with ground-fault circuit interrupters (GFCIs) being that last line of defense of protection; as long as you are lucky enough that this type of protection has been installed and installed correctly. There are many ways to stay safe, we simply need to train our eyes and implement the correct procedures and tools to facilitate it. Read more

Pipe Organs — Standing the Test of Time

by Joseph Wages, Jr.

The National Electric Code, in Article 650, contains the electrical requirements for pipe organs. Pipe organs have been in existence since early Greece in the third century B.C. They were viewed at one time as the greatest of human achievement. But why on earth is there an article in the NEC dealing with these music producing instruments? Read more

Investment Mistakes to Watch for. . . at Different Stages of Life

by Jesse Abercrombie

As an investor, how can you avoid making mistakes? It’s not always easy, because investing can be full of potential pitfalls. But if you know what the most common mistakes are at different stages of an investor’s life, you may have a better chance of avoiding these costly errors. Read more

Mineral-Insulated Cable Is Re-Classified with 2-Hour Fire-Resistive Rating

by Barry O’Connell

In September 2012, both UL and ULC withdrew certification for Electrical Circuit Protective Systems (FHIT and FHITC) that employed fire resistive cables. This included UL Classified Fire Resistive Cable (FHJR), UL Listed cable with "-CI” suffix (Circuit Integrity), and ULC Listed Fire Resistant Cable (FHJRC). Certification was retained for systems that used protective materials like intumescent wraps, tapes, composite mats, etc. Read more

Application and Installation Requirements for Exit Signs: What, Why, and How

by Ark Tsisserev

This subject, similar to many other issues that relate to the application and installation of electrically connected life safety system, is far from being fully understood by the designers, installers and regulators. And certain provisions of the legally mandated documents do not help the Code users. Read more

Improving Electric Vehicle Charging Stations

by Donald E. Bowen, Jr.

As the popularity of electric vehicles (EVs) continues to expand, the demand for charging station availability is also increasing at a rapid rate. EV infrastructure has quickly and quietly sprouted in many urban areas throughout the U.S. and along many interstate highways.

Parallel Conductors Revisited

by Leslie Stoch

High ampacity services and feeders are often installed with conductors in parallel to reduce pulling tensions and for easier handling. I’m sure you are already aware that a long list of conditions comes with permission to parallel conductors. This article reviews the requirements of Rule 12-108 Conductors in Parallel along with some significant changes for such installations now provided in the 2012 Canadian Electrical Code. Read more

The Calling of an Inspector

by Steve Foran

The first time I came eye to eye with a 600-volt system was during the commissioning of a new amusement park. To me, the utility engineer, it was a low voltage system but not so to the customer and indeed 600 volts is a high voltage. Read more

Manual Motor Controllers and Self-Protected Combination Motor Controllers Used in Industrial Control Panels

by Dan Neeser

Some of the most commonly used, but often misunderstood and misapplied devices in industrial control panels are manual motor controllers and self-protected combination motor controllers. The advantage of these devices is the reduced cost and size when compared to traditional motor controllers and combination motor starters.Read more



We’ve got an app for you...

by David Clements

Do you recall the day when personal and business computers first came on the market, along with the notion that they would put people out of work? I can recall buying the first personal computer for my son, a Commodore 64, and not having a clue how to work it; then taking a continuing education class at the local high school on computer basics and programming; and seeing the text "Syntax Error” forever etched into my personal database. Read more

UL Question Corner

Does UL List (Certify) Paint Spray Booths?

by Underwriters Laboratories

UL certifies (Lists) paint spray booths under one of two categories, depending on whether fire protection systems are provided as part of the paint spray booth. The two categories are Paint Spray Booths without Fire Protection Systems for Use in Hazardous Locations (QEFA) and Paint Spray Booths with Fire Protection Systems for Use in Hazardous Locations (QEFY), both are located on page 317 in the 2012 UL White Book or online at Read more

Focus on the Codes

Dry-Type Transformer, Grounding & Bonding Terminations

by Keith Lofland

Grounding and bonding termination points in dry-type transformers are seemingly an issue in that the NEC apparently is silent on where in a dry-type transformer grounding and bonding conductors should be landed (terminated). In addition, many times installers utilize poorly chosen termination means such as installing a lug over a vented portion of the bottom of the transformer. Are there such termination requirements in the NEC and if so, where are they located? Read more

Focus on the Codes

Would the addition of the control circuit conductors in one conduit of this power circuit run in parallel be a violation of having the same number of conductors and the same electrical characteristics

by Jeff Sargent

A parallel conductor branch circuit is run from a switchboard to a 3-phase rooftop air-conditioning unit using two metric designator 63 (2½ in. trade size) conduits with four 4/0 AWG copper conductors (3-phase, 1 EGC) in each conduit. One of the conduits also contains six 10 AWG Class 1, 120-volt control circuit conductors. Would the addition of the control circuit conductors in one conduit of this power circuit run in parallel be a violation of having the same number of conductors and the same electrical characteristics in each conduit? Read more

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