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July-August 2003
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July-August 2003 CoverJuly-August 2003


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Sizing Conductors for All Load Conditions

by Frederic P. Hartwell

One of our primary responsibilities in the electrical trade is to select electrical conductors, and one of the primary responsibilities of electrical inspectors is to judge those selection decisions properly. Recognizing the importance of this issue, the task group appointed to review Article 220 for the 2005 NEC decided to recommend adding a new Example 3A to Annex D covering this topic. It does not focus on load calculations but on conductor selection instead. Unlike most examples, the loads are stipulated,1 the context is industrial, and the distribution is 480Y/277V. The proposal has been endorsed by the NEC Technical Correlating Committee and accepted by CMP-2, subject to public comment as in the case of all proposals. This article uses the setup illustrated in the proposed example (see figure 1 for a visual reference) to present the concepts that need to be mastered. Read more

The Truth About AFCIs, Part III

by George Gregory

Is it a requirement that AFCIs be installed at the time of an electrical service change or upgrade to an existing installation? The enforcement of the AFCI requirements is a common question that must be communicated by the authority having jurisdiction. New dwelling construction or the addition of a bedroom is being consistently enforced as requiring AFCI protection of the branch circuit. The two questions that arise are: 1) Is AFCI required for the addition of an outlet in an existing bedroom? 2) Is the AFCI protection required when a service change / upgrade occurs and the protection of those branch circuits are re-inspected? Read more

Not All Connections are Created Equal – A Focus on Crimping

by Andrew DeIonno

Everyone who designs, builds or services electrical equipment is familiar with a crimp style connector. It is a basic component that is used to either connect or terminate wires. But, as often is the case in engineering, the items that seem simple oftentimes are not, and components that engineers, designers or electricians view as requiring no thought oftentimes cause trouble. This trouble can appear in the design phase, regulatory phase, production phase or during the product life. Read more

Installations and Inspections of Spas and Hot Tubs at Dwellings

by Keith Lofland

One of the most popular inspections in recent years to appear on the local municipal inspector’s daily list is the inspection of spas or hot tubs in the residential setting. Often the dwelling occupant or homeowner has installed the spa or hot tub. This combination of the well-meaning homeowner and the spa or hot tub installation can frequently result in some dangerous situations as far as the electrical requirements are concerned. Maintaining electrical safety and the importance of electrical permits and inspections in these situations cannot be overemphasized. This would apply to the do-it-yourselfers as well as the most seasoned veteran electrician. Read more

Mismatching Wet-niche Swimming Pool Luminaires with Forming Shells Can Be a Shocking Combination

by Steven Holmes

Installing an incompatible wet-niche swimming pool luminaire (lighting fixture) into the forming shell in the wall of a swimming pool or spa can increase the risk of electric shock or injury to the users. The luminaire may physically fit into the forming shell, but the combination may not meet the applicable safety requirements. Read more

A Personal View of NEC Code Making Panel 2

by Thomas L. Harman

It has been my pleasure and responsibility to be a member of National Electrical Code (NEC) code-making panel 2 (CMP-2) for nine NEC code cycles. Over this time, the code-making panels have produced the codes for 1981, 1984, 1987, 1990, 1993, 1996, 1999, 2002 and they are now working on the 2005 edition of the NEC. In this article, I will describe some of my experiences on this panel as well as some of the important code rules that have been introduced into the NEC by CMP-2 over the years. Read more

Proposed Code Changes for the 2005 NEC

by Michael Johnston

It is that time of the Code cycle again. Over 3,580 proposed changes were submitted to the National Fire Protection Association (NFPA) to amend the 2002 National Electrical Code (NEC). The 2005 NFPA-70 committees have been reduced from twenty code-making panels (CMP) to nineteen as a result of shifts in responsibilities in an effort to more evenly distribute the workloads among the panels. Many of the code-making panel responsibilities have not changed. Read more

Neon Midpoint Secondary Return Circuits

by Michael Johnston

Electrical circuit wiring requires building a proper path in which the electrical current can flow. Some fundamentals of electrical circuits are common to all circuits, including high voltage neon secondary circuits. One basic fundamental is that for current to flow, there must be a source (voltage) and a circuit that is complete and connected to the source. It should be understood that current will always try to return to its source. Basically, what goes out must return to the source (transformer or power supply). If the circuit (GTO secondary conductors) is not complete, and both supply and return circuit paths are not connected, the circuit will not work. Read more



Summer Time and The Living is Easy!

by James W. Carpenter

Yes, hot weather is here and one’s thoughts turn to cooling off in the swimming pool. Now we have to make sure the pool water is clear and pure. How much chemical is necessary? How to keep leaves and other matter out of the water is another concern. Getting the pool in shape is almost as important as getting one’s self in shape. After all, we must look good in that new bathing suit. One thing we don’t want to worry about is the electrical system. We don’t expect to feel tingle shocks when we are in or around the pool. We want the pump to run and the lights to work even if they have not been used since last summer. Well, just like the car or any thing else, there are some things that need to be checked along with the water quality. Read more

Canadian Code

Electrical Hazards Within Reach

by Leslie Stoch

The Canadian Electrical Code offers several ways to protect us from electrical shock hazards when electrical equipment may be within reach, in a wet or damp area, or near grounded metal. In some cases, we are asked to maintain "out of reach” distances. When this is impracticable, a Class A ground-fault current interrupter may help to minimize the risk of electrical shock when people find themselves in simultaneous contact with electrical equipment and the earth. A GFCI may serve as a second safety barrier, should the first barrier fail to prevent an electric shock. You will recall that a Class A GFCI will trip in the event of leakage current less than 6 mA, safely within the comfort range of most people. Read more

UL Question Corner

Are Listed wet location polymeric electrode insulator boots for neon lighting

by Underwriters Laboratories

There is one manufacturer that has a UL Listing for a wet location on their boots and it is only acceptable for use with GTO cable sleeving by that same manufacturer. Only the specific combinations identified in the instructions for a Listed polymeric electrode insulator boot have been found suitable for use in wet locations. You should always ask for and refer to the installation instructions provided with the Listed product for the proper component correlation. Read more

Other Code

Safety Sign Placement on Large Substation

by David Young

The National Electrical Safety Code (NESC) in Rule 110A1 describes the type of enclosure necessary to surround an electric supply substation. "Rooms and spaces in which electric supply conductors or equipment are installed shall be so arranged with fences, screens, partitions, or walls to form an enclosure as to limit the likelihood of entrance by unauthorized persons or interference by them with equipment inside.” The rule also requires posting of a safety sign at each entrance and one on each side of fenced enclosures. A "NOTE” informs readers that American National Standards Institute (ANSI) standards Z-535.1, .2, .3, .4, and .5 contain information regarding safety signs. Read more

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