Questions and Answers
Flexible cords and cables shall be protected against overcurrent in accordance with their capacities.
True
Plug fuses have a voltage rating of _____V between conductors in most applications.
125
All conductors installed in electrical distribution systems shall be insulated.
False
THW conductors are permitted to be installed in wet locations.
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Conductors used for direct burial shall be identified for such use.
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Insulated conductors installed in wet locations shall be of a type _____ for the use.
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A(n) _____ fuse is a plug fuse that incorporates a screw configuration that is interchangeable with fuses of other ampere ratings.
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When used for equipment grounding purposes, only covered or insulated conductors are permitted.
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No conductor shall be installed in such a manner that the operating temperature of its ______ is exceeded.
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When conductors are run in parallel in separate raceways, the raceways shall have the same _____ characteristics.
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Plug fuses of 15 A and lower are identified by a(n) _____ configuration of the fuse window.
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Circuit breakers shall clearly indicate whether they are in the open or closed position.
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Overcurrent protective devices are permitted to be installed in clothes closets if they are located at least 12" from combustible materials.
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Circuit breakers used as switches for a 120 V fluorescent lighting circuit shall be listed and marked 'SWD' or 'HID'.
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Cartridge fuses with no markings are rated for _____A.
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Circuit breakers that are not marked have an interrupting rating of ______A.
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________ conditions included installations where the conductors are exposed to oils, greases, vapors, etc. that break down the integrity of the conductors' insulation.
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Ampacity of feeder taps not over 25' shall not be less than 1/3 of the rating of the overcurrent protective device protecting the ______ conductors.
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In general, fuses and circuit breakers shall not be connected in ______.
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Equipment grounding conductors, in general when they are insulated, shall be provided with an outer finish that is ______ in color.
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A(n) ________ is a circuit breaker with an intentional delay between the time when the fault or overload is sensed and the time when the CB operates.
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In general, insulated grounded conductors (neutral) sizes 6 AWG or smaller shall be identified with an outer finish that is white or _______.
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The three basic classifications of insulation rating are 60C (140F), 75C (167F), and ________ C (194F).
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The next ________ standard size OCPD of 800 A or less is permitted to be used where the OCPD does not correspond to a standard size.
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Overcurrent devices are permitted in bathrooms.
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Copper and aluminum conductors shall not be terminated in a manner that causes the dissimilar metals to come in direct contact with each other.
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Paralleled conductors shall all be the same length.
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_______ is generated when current flows through a conductor.
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A(n) ______ is any current in excess of that for which the conductor or equipment is rated.
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______ AWG and larger ungrounded conductors installed in a raceway that enters a box shall be protected by an identified insulating fitting.
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The least potentially damaging overcurrent occurs when there is an overload.
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The maximum standard rating for a fuse is 5000 A.
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Type S fuses are designed for circuits not exceeding 100 V.
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Insulated conductors are the most common conductors installed in electrical systems.
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Locations can be classified as either dry, ______, or wet.
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Study Notes
Flexible Cords and Cables
- Flexible cords and cables must be protected against overcurrent according to their capacities.
Fuse Ratings
- Plug fuses typically have a voltage rating of 125V between conductors in most settings.
- Cartridges fuses without markings possess a rating of 10,000A.
- Circuit breakers that lack markings have an interrupting rating of 5,000A.
Conductors and Insulation
- Not all conductors in electrical distribution systems are required to be insulated.
- THW conductors are allowable in wet locations, while conductors for direct burial must be explicitly identified for such use.
- Insulated conductors in wet conditions must be of a type that is listed for the intended use.
- Size 6 AWG or smaller insulated grounded conductors should have an outer finish that is white or grey.
Equipment Grounding and Circuit Breakers
- When used for equipment grounding purposes, the use of covered or insulated conductors is not mandatory.
- Circuit breakers should clearly indicate their open or closed position, and when employed as switches for 120V fluorescent circuits, they must be labeled "SWD" or "HID".
- Equipment grounding conductors should generally have green outer finishes when insulated.
Overcurrent Protection
- Overcurrent protective devices should not be installed in bathrooms and must not connect fuses and circuit breakers in parallel.
- The ampacity of feeder taps that do not exceed 25 feet should not fall below one-third of the overcurrent device rating supervising the feeder conductors.
Conditions and Classifications
- Corrosive conditions include scenarios where conductors are exposed to damaging substances such as oils or greases.
- Insulation ratings are classified into three basic types: 60C (140F), 75C (167F), and 90C (194F).
- Locations are categorized as dry, damp, or wet.
Current and Heat Generation
- Heat is produced when current passes through a conductor, and any current exceeding the conductor's rating is termed "overcurrent".
Miscellaneous
- Paralleled conductors must all be of the same length.
- The maximum standard rating for a fuse is not 5000A, and Type S fuses are suitable for circuits that exceed 100V.
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Description
Test your understanding of key concepts from NEC Chapter 5 with these review questions. This quiz covers essential topics including protection of flexible cords and the requirements for conductors in electrical distribution systems. Perfect for students and professionals looking to reinforce their knowledge.
