The arc-fault circuit-interrupter (AFCI) has been around for three National Electrical Code (NEC) cycles and, with the advent of the new 2005 NEC, will have been present in three editions, although with various changes within each edition.
Ground-fault sensing and relaying equipment is intended for use in power distribution systems rated at 600V maximum and are considered to be equipment protection devices, not personal protection devices.
Contractors need to develop highly specialized knowledge Healthcare facilities present the potential for financial gain for properly qualified electrical contractors. These projects also present a downside of risk of increased liability due to the nature of the projects and potential damages.
In many conversations with electrical inspectors on the subject of arc-fault circuit-interrupters (AFCIs), I find them variously questioning, doubtful, confused, bewildered and puzzled concerning the application of 210.12.
Cooking Equipment Calculations, Part III 220.19 Electric Ranges and Other Cooking Appliances Article 220 of the National Electrical Code contains specifications for calculating branch-circuit, feeder and service loads.
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.
Specifications for calculating branch-circuit, feeder and service loads are in Article 220 of the National Electrical Code. This article is divided into four parts: I. General, II. Feeders and Services, III. Optional Calculations for Computing Feeder and Service Loads and IV.
Article 220 contains provisions for calculating branch-circuit, feeder and service loads. Following the requirements set forth in this article will provide the minimum size branch circuit, feeder or service.
There’s a problem that is either right in front of us or lurking around the corner. The problem involves data communications cabling above drop ceilings in commercial buildings—some of that old cable has been accumulating in ceiling spaces for years and years.
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.
Owners often contact contractors to install fire alarm systems in existing buildings. And, just as often, the Code does not require these installations. Rather, the building owner simply wants a fire alarm system installed for his or her own peace of mind.