You are urged to check with the standards organizations or governmental authorities for further information and access to definitive versions of these important laws.
Criminal penalties may apply for noncompliance. Uploaded by Public Resource on July 11, Internet Archive's 25th Anniversary Logo. Search icon An illustration of a magnifying glass. Comprehensive coverage, an innovative learning approach perfect for today's visual learners, and accurate, up-to-date information make this valuable resource indispensable for beginning and experienced electricians, engineers, and other electrical professionals.
Important Notice: Media content referenced within the product description or the product text may not be available in the ebook version. Download Torrent Beyond Glory UL, the standard for AFCIs needs improvement to assure immunity to lighting equipment as well as many other common devices. Open navigation menu. Close suggestions Search Search. User Settings. Skip carousel. Carousel Previous. Carousel Next. What is Scribd? Explore Ebooks. Bestsellers Editors' Picks All Ebooks.
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Popular Books. Twelve Days of Christmas by Debbie Macomber. Pandemia by Alex Berenson. The NFPA also publishes a 1,page NEC Handbook for each new NEC edition that contains the entire code, plus additional illustrations and explanations, and helpful cross-references within the code and to earlier versions of the code. The explanations are only for reference and are not enforceable. Many NEC requirements refer to 'listed' or 'labeled' devices and appliances, and this means that the item has been designed, manufactured, tested or inspected, and marked in accordance with requirements of the listing agency.
Upon payment of an investigation fee to determine suitability, an investigation is started. To be labeled as fit for a particular purpose for example 'wet locations', 'domestic range' a device must be tested for that specific use by the listing agency and then the appropriate label applied to the device.
A fee is paid to the listing agency for each item so labeled, that is, for each label. Most NRTLs will also require that the manufacturer's facilities and processes be inspected as evidence that a product will be manufactured reliably and with the same qualities as the sample or samples submitted for evaluation.
An NRTL may also conduct periodic sample testing of off-the-shelf products to confirm that safety design criteria are being upheld during production. Because of the reputation of these listing agencies, the 'authority having jurisdiction' or 'AHJ' — as they are commonly known usually will quickly accept any device, appliance, or piece of equipment having such a label, provided that an end user or installer uses the product in accordance with manufacturer's instructions and the limitations of the listing standard.
However, an AHJ, under the National Electrical Code provisions, has the authority to deny approval for even listed and labeled products. Likewise, an AHJ may make a written approval of an installation or product that does not meet either NEC or listing requirements, although this is normally done only after an appropriate review of the specific conditions of a particular case or location.
The Code has user-friendly features to aid the reader in seeing changes. Revisions or additions to the articles from the version are highlighted in gray shading. The electric code makes a distinction between 'high' voltages volts and higher , and 'low' voltages below that, and which have two different safety classifications and regulations. For circuits defined as low voltage, in some jurisdictions, there is no requirement for licensing, training, or certification of installers, and no inspection of completed work is required, for either residential or commercial work.
Low voltage cabling run in the walls and ceilings of commercial buildings is also typically excluded from the requirements to be installed in protective conduit. The precise reasoning for the selection of volts as the division between high and low is not clearly defined, but appears to be based on the idea that a person could touch the wires carrying low voltage with dry bare hands, and not be electrocuted, injured, or killed.
This is generally true for 12 volt systems, but becomes more ambiguous as the voltage increases to volt. The meaning also varies when alternating current is used, as there is the more commonly known root mean square voltage V but also a peak wave voltage V. Telephones for example use low voltage cabling, but the ringing voltage from the central office is approximately 90 volts peak AC and has an RMS voltage of 63 V. In more recent terms, the upper cutoff for what is considered low is approximately 50 Volts, with most computer network equipment operating at 48 Volts DC or lower, and not requiring special training to connect or use.
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