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

Articles by Mark C. Ode

April 2016
As Section 110.2 States, The National Electrical Code (NEC) provides installation requirements for electrical conductors and equipment that are either required or permitted to be installed. However, these conductors and equipment are only acceptable if the installation is approved. NEC Article 100 defines “approved” as being acceptable to the authority having jurisdiction. READ MORE
  • Dry-type cast-resin transformer
March 2016
There are many types of transformers with just as many different uses. Transformers can be installed within electrical equipment, as separate individual transformers, as polyphase banks of two or more single-phase transformers operating as one unit, as exposed coils, or completely enclosed with or without ventilating openings. READ MORE
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.
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.
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.
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