Mark C. Ode

Fire/Life Safety Columnist and Code Contributor

Mark C. Ode is a lead engineering associate for Energy & Power Technologies at Underwriters Laboratories Inc.and can be reached at 919.949.2576 and Mark.C.Ode@ul.com.

Articles by Mark C. Ode

February 2016
Transfer switches are the unsung and often neglected heroes of emergency, legally required standby and optional standby systems. The much larger generators and other alternate-power sources often overshadow these switches, but ultimately, these devices sense normal power loss and activate the generator or alternate power source to critical loads.
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January 2016
Storage batteries are used for many different types of electrical equipment throughout the National Electrical Code (NEC). The phrase “storage batteries” occurs in 13 locations in the NEC index. In addition, Article 480 is devoted to the installation requirements for storage batteries.
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December 2015
The National Electrical Code (NEC) mentions cathodic protection only once; however, dealing with cathodic action and protection can be difficult to diagnose and time-consuming to fix. The 1999 NEC first introduced cathodic protection in 250.6, generally dealing with objectionable current, and specifically in 250.6(E) as isolation of objectionable direct current (DC) ground currents. READ MORE
November 2015
The National Electrical Code (NEC) uses the word “harmonic” exactly 11 times, all in combination with or explanation of neutral conductors. However, “harmonic” is not defined in the NEC. READ MORE
October 2015
National Electrical Code (NEC) 110.26(C)(3) requirements, which cover means of egress from electrical equipment rooms, used to be straightforward. However, two major changes to this section in the 2014 NEC involve panic hardware and the ampere (A) threshold level of the electrical equipment in equipment rooms, and they are a bit complicated.
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September 2015
For my December 2005 column in ELECTRICAL CONTRACTOR, I wrote about the installation of parallel conductors in a metal wireway and the subsequent heating effects. These heating effects occur whether the parallel conductors are installed in a metal or nonmetallic wireway or in an auxiliary gutter. READ MORE
August 2015
New text in section 424.66(A) of the 2014 National Electrical Code (NEC) covers working space for electrical enclosures of resistance heating-element-type duct heaters mounted on air-duct systems in limited-access areas. New subsection 424.66(B), Limited Access, addresses examination, adjustment, servicing or maintenance while energized. READ MORE
July 2015
Safety for solar photovoltaic (PV) systems has come a long way since the first installation requirements were inserted as Article 690 into the 1984 National Electrical Code (NEC). Between the 1984 NEC and the 2014 edition, there have been hundreds of proposals and comments to change the requirements in Article 690, and many of these suggested changes have been implemented into the NEC. READ MORE
June 2015
During the recent 2017 National Electrical Code (NEC) first revision meetings in Hilton Head, S.C., a number of public inputs were submitted to introduce a new cabling system into Article 725 and Article 760. Article 725 covers Class 1, 2 and 3 remote control, signaling and power-limited circuits, and Article 760 covers nonpower-limited and power-limited fire alarm circuits. READ MORE

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