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

May 2012
I started this series of articles after a friend asked some questions about overcurrent protection for the direct current (DC) output of photovoltaic (PV) modules, the DC output of combiner boxes, the location of disconnects for both the DC side and the alternating current (AC) side of the inverter, and the sizing of conductors on both sides. READ MORE
February 2012
In the past few cycles of the National Electrical Code (NEC), there have been numerous and substantial changes involving dwelling-unit receptacles and lighting outlets in 210.52 with general layout requirements in Part III enhanced by these text changes. READ MORE
January 2012
In the past few editions of the National Electrical Code (NEC), light-emitting diode (LED) illumination systems have been inserted into almost every article where lighting is mentioned. Continuing that trend in the 2011 NEC, Article 410 (luminaires) and Article 600 (electric signs and outline lighting) have been updated with additions concerning LEDs. READ MORE
December 2011
Hurricane season is over, and the inundation of floodwaters in many parts of the country has likely receded by now. However, evaluating electrical equipment that has been subjected to water and determining whether to recondition the equipment or replace it remains a serious issue. READ MORE
November 2011
Arc-fault circuit interrupter (AFCI) protection was originally proposed for the 1996 National Electrical Code (NEC) by the Electronic Industry Association, but it failed to receive enough votes during the adoption process. The electronic and electrical industry spent time and money and used extremely qualified technical experts to develop and test AFCI circuit breakers. READ MORE
September 2011
Most electrical equipment requires physical connection to electrical conductors as a major part of the installation process. READ MORE
August 2011
As part of the development of the low-voltage lighting power-grid system, coverage and acceptance of the new system within the standards community becomes paramount, since this product is new and innovative. READ MORE
July 2011
There is a new technology using low-voltage lighting power distribution at 30 volts (V) or less where the suspended ceiling grid is a lighting power distribution system. Article 410, covering luminaires, and Article 411, covering low-voltage lighting systems at 30V or less, are the two primary lighting installation articles in the National Electrical Code (NEC) pertaining to this new technology. READ MORE
June 2011
In the past few years, hundreds of thousands of solar photovoltaic (PV) systems have been installed for residential (dwelling) units, commercial buildings, industrial facilities and utility companies. Many have been subsidized by grants from utility companies as well as by local, county, state and federal tax rebates. READ MORE