Tenants of the Time & Life Building in New York’s Rockefeller Center include Time Inc., publisher of more than 100 magazines. In an effort to “green” the building, shaft grounding rings have been installed to protect the bearings of HVAC fan motors. Proper tuning of a variable frequency drive’s output range and proper grounding of [...]
Rule 10-812 specifies minimum grounding conductor sizes for low-voltage electrical systems up to 750 volts. This article discusses the complexities of this rule, which as you know, was revised in the 2009 Canadian Electrical Code.
When buying real estate, conventional wisdom dictates the three most important elements are—Location, Location, and Location. Based on my twenty-six years of working with PV systems, including the school of hard knocks, I strongly feel that the three most important elements to long- and short-term PV safety are—Grounding, Grounding, and Grounding. Utility-interactive residential (dwelling unit), [...]
Power continuity is essential in wind power projects where a tripped overcurrent device due to ground fault can have serious economic or operational consequences. An arcing phase-to-ground fault can totally destroy the equipment. Consequential downtime adds to the economic loss. Four typical grounding methods for generators and power systems are examined for these factors and [...]
Continuous improvement takes place throughout our lives. We learn from our mistakes and as we gain experience, we try hard to avoid repeating them. Without looking too hard, we can usually identify where our decisions could have been better. The Canadian Electrical Code, under continual review, is no exception. This article discusses some places where [...]
If you were to open an unopened jar, does that jar still qualify as “unopened”? No one would argue the fact that the moment I lock an unlocked door, that door is no longer “unlocked.” I must confess that this author has yet to come across an uneaten piece of cake and left that cake [...]
This article looks at Rule 10-814 and the bonding conductor sizes given in Table 16 as they apply to resistance grounded systems. We’ll review the question—are the Table 16 minimum wire sizes appropriate when maximum available ground faults are limited by resistance grounding, or are there any circumstances when bonding conductors might need to carry [...]
In today’s electrical environment, many installed ground rod electrodes do not meet the requirements of the National Electrical Code. Ground rods less than 0.625 in diameter, rods that were cut in half either because of driving difficulty or to reduce expenses, or rods with less than the required coating thickness (e.g., copper, zinc) are all [...]
Protection Required There’s a lot of talk about protection going on currently. Personal protection, internet protection, home protection, neighborhood protection… the list goes on and on. Because results of a recent IAEI members survey show interest in more basic code training, this article will focus on a basic but essential requirement for most any electrical [...]
The CE Code requirements for bonding and grounding are perhaps, the most important safety rules for electrical installations. Each person deemed to be qualified to do electrical work must clearly understand what bonding and grounding is, why it is necessary and how it must be done. And yet the basic principles of these essential code [...]
Abstract A variety of different electrodes is used for providing effective and safe electrical grounding. The ability of these electrodes to resist corrosion determines their useful service life. Copper-bonded steel and galvanized steel electrodes have been used for decades yet there is still much debate regarding the relative corrosion performance of each type of coating [...]
Photovoltaic (PV) systems will be producing hazardous voltages and currents for 50 years or more. Over that period of time, they may or may not be operational and they may or may not be maintained. Proper grounding of all exposed metal surfaces in the system that may be energized by internal faults, poor terminations or [...]
A significant change occurred in the 2008 National Electrical Code (NEC) at Section 250.32(B) pertaining to the acceptable grounding methods at buildings or structures supplied by a feeder or branch circuits from a grounded service located at another building or structure supplied from a common service. In this article, we will take a closer look [...]
Electrical systems and equipment are grounded to achieve a greater level of safety from electrical hazards to persons and property. Article 250 of the NEC provides the minimum requirements for grounding and bonding electrical systems and equipment. NEC-2008 has incorporated revisions related to electrical grounding and bonding terminology that results in improved clarity and usability [...]
Once upon a time (the 1987 Code cycle) in the land of Quincy, a group of alchemists from a national laboratory was elaborating on the excellence of their photovoltaic (PV) test facility in the distant Land of Enchantment. They showed some senior firefighters a picture of a burned PV module that had been subject to [...]
