Article 90
What 5 things does the NEC NOT Cover?
(1) Installations in ships, watercraft other than floating buildings, railway rolling stock, aircraft, or automotive vehicles N in other than mobile homes and recreational vehicles. (2) Installations underground in mines and self-propelled mobile surface mining machinery and its attendant electrical trailing cable (3) Installations of railways for generation, transformation, transmission, energy storage, or distribution of power used exclusively for operation of rolling stock or installations used exclusively for signaling and communications purposes (4) Installations of communications equipment under the exclusive control of communications utilities located outdoors or in building spaces used exclusively for such installations (5) Installations under the exclusive control of an electric utility where such installations a. Consist of service drops or service laterals, and associated metering, or b. Are on property owned or leased by the electric utility for the purpose of communications, metering, generation, control, transformation, transmission, energy storage, or distribution of electric energy, or c. Are located in legally established easements or rightsof-way, or d. Are located by other written agreements either designated by or recognized by public service commissions, utility commissions, or other regulatory agencies having jurisdiction for such installations. These written agreements shall be limited to installations for the purpose of communications, metering, generation, control, transformation, transmission, energy storage, or distribution of electric energy where legally established easements or rights-of-way cannot be obtained. These installations shall be limited to federal lands, Native American reservations through the U.S. Department of the Interior Bureau of Indian Affairs, military bases, lands controlled by port authorities and state agencies and departments, and lands owned by railroads. [90.2B]
What 4 things are covered by the NEC for the installation and removal of electrical conductors, equipment, and raceways; signaling and communications conductors, equipment, and raceways; and optical fiber cables and raceways?
(1) Public and private premises, including buildings, structures, mobile homes, recreational vehicles, and floating buildings (2) Yards, lots, parking lots, carnivals, and industrial substations (3) Installations of conductors and equipment that connect to the supply of electricity (4) Installations used by the electric utility, such as office buildings, warehouses, garages, machine shops, and recreational buildings, that are not an integral part of a generating plant, substation, or control center. [90.2A]
How many chapters are in the NEC?
9. [90.3]
What is Hard Conversion?
A change in dimensions or properties of an item into new sizes that might or might not be interchangeable with the sizes used in the original measurement. [90.9DIN1]
What is a Soft Conversion?
A direct mathematical conversion and involves a change in the description of an existing measurement but not in the actual dimension. [90.9DIN1]
What Chapters apply to special occupancies, special equipment, or other special conditions and may supplement or modify the requirements in Chapters 1 through 7?
Chapters 5,6,7. [90.3]
What does Chapter 8 cover?
Communications systems and is not subject to the requirements of Chapters 1 through 7 except where the requirements are specifically referenced in Chapter 8. [90.3]
What is the NEC not intended for?
Design specification or an instruction manual for untrained persons. [90.1A]
T/F Compliance with NEC code provisions will ensure installation is efficient, convenient, or adequate for good service or future expansion of electrical use.
False [90.1B]
What does an initial adequate installation and reasonable provisions for system changes provide?
For future increases in the use of electricity. [90.1B IN]
Why are Informative Annexes A-J added? Are they part of the requirements of the NEC?
For informational purposes only. No. [90.3]
What may the Authority Having Jurisdiction make an exception for?
For the installation of conductors and equipment that are not under the exclusive control of the electric utilities and are used to connect the electric utility supply system to the service conductors of the premises served, provided such installations are outside a building or structure, or terminate inside at a readily accessible location nearest the point of entrance of the service conductors. [90.2C]
What does IEC 60364-1, Section 131 contain that is addressed by the NEC?
Fundamental principles of protection for safety that encompass protection against electric shock, protection against thermal effects, protection against overcurrent, protection against fault currents, and protection against overvoltage. [90.1C IN]
How do Chapters 1 -4 Apply?
Generally. [90.3]
Which organizations is the NEC suitable for mandatory application for including signal and telecommunications systems? Who else is the NEC intended for?
Governmental bodies exercising legal jurisdiction over electrical installations. Use by insurance inspectors. [90.4]
How will conversions from inch pounds to SI be made?
Hard conversion except as provided from 90.9C. [90.9B]
What document is the basis for SI conversions?
IEEE/ ASTM SI 10-1997, Standard for the Use of the International System of Units (SI): The Modern Metric System. [90.9DIN2]
When is the use of soft conversion permitted?
In instances where a negative impact on safety exists. [90.9C4]
What often causes the overloading of wiring systems or usage not in accordance with the NEC? What is this?
Initial wiring did not provide for an increase in the use of electricity. A hazard. [90.1B IN]
What does compliance with the NEC code provisions and proper maintenance ensure?
Installation is essentially free from hazard. [90.1B]
What does the Authority having Jurisdiction for the NEC have responsibility for?
Making interpretations of the rules, for deciding on the approval of equipment and materials, and for granting the special permission contemplated in a number of the rules. [90.4]
What is the purpose of limiting the number of circuts in a single enclosure?
Minimizes the effects from a short circuit or ground fault. [90.8B]
What is the preferred units of measurement in the NEC?
Modernized Metric System aka International System of Units (SI). [90.9A]
What document provides the guidelines for style and language of the NEC?
NFPA Style Manual. [90.5C IN]
Is The context of extracted material of other standards permitted to be compromised? When is the editing of extracted material permissible?
No. In order to match the style of the NEC. [90.9C2]
What type of information do the Informative Annexes contain?
Nonmandatory information relative to the use of the NEC. [90.5D]
What should exist when planning future expansion?
Plans and specifications that provide ample space in raceways, spare raceways, and additional spaces allow for future increases in electric power and communications circuits. [90.8A]
Why are examinations for safety made under standard condition for items specifically referenced in the NEC? How is this promulgated? What does this avoid?
Provide a basis for approval where the record is made generally available. By organizations properly equipped and qualified for experimental testing, inspections of the run of goods at factories, and service-value determination through field inspections. Avoids the necessity for repetition of examinations by different examiners, frequently with inadequate facilities for such work, and the confusion that would result from conflicting reports on the suitability of devices and materials examined for a given purpose. [90.7]
Where should distribution centers be located in order to provide convenience and safety of operation?
Readily Accessible Areas. [90.8A]
When using a dual system of measurements which shall come first?
SI units shall appear first, and inchpound units shall immediately follow in parentheses. [90.9B]
What International Code do the requirements of the NEC address for the fundamental principles of protection for safety?
Section 131 of International Electrotechnical Commission Standard 60364-1, Electrical Installations of Buildings. [90.1C]
What does Chapter 9 Consist of?
Tables that are applicable as referenced. [90.3]
What is the intent of the NEC concerning factory-installed internal wiring or the construction of equipment?
That they need not be inspected at the time of installation of the equipment, except to detect alterations or damage, if the equipment has been listed by a qualified electrical testing laboratory. [90.7]
Who by special permission may waive the requirements of the NEC or propose alternative methods where it is assured that equivalent objectives can be achieved by establishing and maintaining effective safety?
The Authority Having Jurisdiction [90.4]
What is the purpose of the National Electrical Code
The practical safeguarding of persons and property from hazards arising from the use of electricity. [90.1A]
If new products, constructions, or materials that may not yet be available at the time that the NEC is adopted, what may the Authority Having Jurisdiction permit?
The use of the products, constructions, or materials that comply with the most recent previous edition of the NEC adopted by the jurisdiction. [90.4]
What is Explanatory Information within the NEC? How is it Denoted? Is it enforcable?
Things such as references to other standards references to other sections of the code and other informational material. Denotes by use of INFORMATIONAL NOTES. NO. [90.5C]
What are permissive rules in the NEC? What are they denoted by?
Those that identify actions that are allowed but not required, are normally used to describe options or alternative methods. Denoted by SHALL BE PERMITTED or SHALL NOT BE REQUIRED. [90.4B]
What are Mandatory Rules in the NEC? What denotes them as such?
Those that identify actions that are specifically required or prohibited. Denoted by SHALL or SHALL NOT. [90.5A]
Why have formal interpretation standards been established? Where are they found?
To promote uniformity of interpretation and application of the provisions of the NEC. NFPA Regulations Governing Committee Projects [90.6]
T/F The NEC contains provisions that are considered necessary for safety.
True [90.1B]
When is the inclusion of SI units not required?
Where industry practice is to express in inch pounds. [90.9C3]
When shall Trade Size designator be used rather than dimensions?
Where the actual measured size of a product is not the same as the nominal size. [90.9C1]
Does compliance with either SI units or Inch Pounds Units constitute Compliance with the NEC?
Yes. [90.9D]
Is the conversion from inch pound units and SI units permitted to be an approximation?
Yes. [90.9D]