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

Articles by Mark C. Ode

February 2004
Many changes have occurred to the National Electrical Code (NEC) since the first NEC was published on Aug. 31, 1897. Even though the electrical industry was in its infancy, this “first” NEC was remarkably insightful and has withstood the test of time. Despite the many changes since the first NEC was established, some of the original requirements are still found in the 2002 NEC. READ MORE
January 2004
At one time or other, all contractors have been faced with a decision to either recalculate the size of an existing service or feeder or just guess at the amount of spare load and install new circuits while hoping for the best. Guessing will usually only get you in trouble. READ MORE
December 2003
This is the conclusion of a two-part article that began in the November issue. This part provides important information for listing and National Electrical Code requirements for installations of emergency, legally required standby and optional standby systems. READ MORE
November 2003
This is the first of two parts about installing emergency, legally required and/or optional standby systems. This first part will cover the basics of the three systems and the second part will cover requirements for transfer equipment. READ MORE
October 2003
Many new concepts in lighting control ARE being used by designers and electricians, while other new designs are still relatively unknown. New switches have been developed that can provide control of individual luminaires or lighting circuits while interfacing with microprocessors that will provide both timing, dimming and mood setting of luminaires in multiple locations. READ MORE
September 2003
Article 410 in the National Electrical Code (NEC) covers the installation of the wiring and the equipment forming the parts of lamps, luminaires (fixtures) and lampholders. There are both general requirements for luminaire installations as well as specific requirements found in this article and it covers a variety of luminaires. READ MORE
August 2003
Supplemental and supplementary grounding electrodes are very similar in name but vastly different in their permitted uses. Understanding the differences in these two electrodes can be critical in providing a safe, Code-compliant installation. Grounding electrodes provide four basic functions in a grounded electrical system and are extremely important for the safe operation of the system. READ MORE
June 2003
A luminaire is defined in Article 100 as “a complete lighting unit consisting of a lamp or lamps together with the parts designed to distribute the light, to position and protect the lamps and ballast (where applicable), and to connect the lamps to the power supply.” Since luminaires (lighting fixtures) were not previously defined before the 2002 NEC, this new definition is meant to cover all aspe READ MORE
May 2003
Article 305 for temporary wiring in the 1999 National Electrical Code has been relocated to Article 527 covering temporary installations in the 2002 NEC. At first glance, relocating an article from Chapter 3 to Chapter 5 would appear to be a subtle change with little effect on temporary installations. However, this change does affect the use of NM cable as a temporary wiring method. READ MORE