James G. Stallcup

Code Contributor

James G. Stallcup is the CEO of Grayboy Inc., which develops and authors publications for the electrical industry and specializes in classroom training on the NEC and OSHA, as well as other standards. Contact him at 817.581.2206.

Articles by James G. Stallcup

May 2008
Recently, an inspector and contractor called me concerning a 277/480-volt feeder circuit that was designed to comply with the 2008 National Electrical Code (NEC) and supplied a building from the service equipment located in a substation switchboard room. In this installation, the grounded conductor was to serve as a neutral plus an equipment-grounding means. READ MORE
April 2008
There were 3,688 proposals for changes to the newest National Electrical Code (NEC) and 2,349 comments processed by the National Fire Protection Association (NFPA) staff at NFPA headquarters in Quincy, Mass. The following is part four in a series of significant changes for the 2008 NEC. READ MORE
April 2008
While I was teaching a seminar for the National Fire Protection Agency (NFPA), a student asked a series of interesting questions. Basically, the student wanted to know where in the National Electrical Code (NEC) were the requirements that permitted a general-purpose enclosure to be installed containing hermetically sealed contacts. READ MORE
March 2008
JaeI receive many questions on how to design and install the electrical system for a separately derived system, including the use of the grounded neutral conductor. Naturally, grounding and bonding the secondary side always is a major issue as well as how the neutral conductor is used. READ MORE
February 2008
The 2008 National Electrical Code (NEC) has been revised by declaring the appropriate procedure for calculating the load to size the neutral conductor. There has always been a controversy between designers on the application of the NEC concerning this calculation. READ MORE
January 2008
This is a continuation of my last column, which was about the different types of purged and pressurized systems used in modern control rooms. Electrical control components and instrumentation devices and other equipment located in control rooms at refineries, chemical plants and similar facilities also are suitable for use in hazardous or classified locations. READ MORE
December 2007
Recently, an electrical contractor and his foreman visited my office to talk about electrical equipment installed in hazardous locations, specifically about explosion-proof, intrinsically safe and nonincendive equipment as well as purged and pressurized systems. They wanted an explanation of their types and use. READ MORE
November 2007
Members of a workshop I instructed on the National Electrical Code (NEC) asked me how to determine the ampacities of conductors based on how they are used in the electrical system. Covering all the Code sections that listed such requirements helped, so I decided to outline these rules in this month’s Code Comments column. READ MORE
October 2007
Protection for transformers rated 600 volts or less is determined by selecting one of three levels of full load current (FLC) found in Table 450.3(B) of the National Electrical Code (NEC). Levels are based on either primary protection only or by providing both primary and secondary protection. READ MORE