Recently on a cross-country flight, I noticed the incredible number of alternative power sources that are in the process of being installed or have already been installed and are in operation. From the air, it was easy to recognize why the wind generators are placed in long lines along cliffs and in areas where natural air movement power the generators. READ MORE
Mark C. Ode
Fire/Life Safety Columnist and Code Contributor
Mark C. Ode is a staff engineering associate at Underwriters Laboratories Inc., based in Peoria, Ariz. He can be reached at 919.949.2576 and mark.c.ode@us.ul.com.
Articles by Mark C. Ode
November 2009
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Based on a new requirement in Section 210.8(B)(5) of the 2008 National Electrical Code (NEC), all 125-volt, single-phase, 15- and 20-ampere receptacles installed within 6 feet or 1.8 meters of the outside edge of a sink in a commercial or industrial facility must be covered by ground-fault circuit interrupter (GFCI) protection for personnel. READ MORE
October 2009
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The 20th and 21st centuries have seen many changes in gasoline stations. READ MORE
September 2009
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The purpose of ground-fault protection on temporary wiring installations during construction, remodeling, maintenance, repair or demolition of buildings, structures or equipment is to ensure personnel protection. Section 590.6 re-quires ground-fault circuit interrupter (GFCI) protection for any temporary power source supplying electrical equipment on the job site. READ MORE
August 2009
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In section 250.52(A)(2) of the 2005 and the 2008 editions of the National Electrical Code (NEC), the metal frame of a building or structure is considered to be a grounding electrode if the metal frame is connected to earth by one of four different methods. Upon analyzing the four different methods, many electricians’ question whether the four methods provide an appropriate connection to earth. READ MORE
July 2009
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Recently, I fielded a question about the basic statement in Section 695.3 of the 2008 National Electrical Code (NEC) that “electric motor-driven fire pumps shall have a reliable source of power.” The question involved the reliability of the power source for one of the most important electrical motors in a building. READ MORE
May 2009
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While preparing a presentation, I noticed a photo taken at a facility where temporary power was needed periodically. The facility rented a generator when necessary. It showed a disconnecting means with four individual conductors stubbed out of the bottom of the enclosure. READ MORE
March 2009
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Many are aware that electrical equipment arcing and sparking -can cause chemical atmospheres (gases, vapors and dusts) to ignite. However, we often forget that thermal ignition of these chemical atmospheres also can occur if the chemicals are exposed to high temperatures. READ MORE
February 2009
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A requirement for short-circuit current rating was added in the 2005 National Electrical Code (NEC) to Section 430.8 covering motor controller marking, to Section 440.4(B) covering controller marking for air conditioning and refrigerating equipment, and to 409.110 covering controller marking for industrial control panels. READ MORE