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Conductor Insulation Properties: Table _____ of the NEC provides information on conductor properties such as permitted use, maximum operating temperature and other insulation details.
TW can be described as thermoplastic insulation, suitable for dry or wet locations with a maximum operating temperature of 60 degrees C(True/False)
TFFN can be described as stranded fixture wire with thermoplastic insulation, nylon cover. (True/False)
The ampacity of a conductor is ed in table _____ under the condition of no more than three current carrying conductors bundled together in raceway, cable or earth an ambient temperature of 86 degrees F.
The ampacities ed in Table 310.15(b)(16) are based on temperature alone and do not take _____ into account.
Voltage drop considerations are for ________ and not for safety; therefore, sizing conductors for voltage drop is not a Code requirement.
Efficiency of operation
The smallest size conductor permitted by the NEC for branch circuits, feeders or services is _____ copper or _____ aluminum.
No. 14, No. 12
When selecting a conductor for a circuit, always select the conductors not smaller than the _______ of the equipment.
(110-14(c)(1) ) Equipment rated at 100 ampere or less shall have the conductor sized no smaller than _____ degrees C unless the terminals are marked otherwise.
(110-14(c)(1) )What size THHN conductor is required for a 50 ampere circuit, ed for use at 60 degrees C?
(110-14(c)(2) )Terminals for equipment rated over 100 ampere and pressure connector terminals for conductors larger than No. 1 shall have the conductor sized according to the _____ temperature rating ed in Table 310.15(B)(16)
Parallel conductors (electrically joined at both ends) permit a smaller ________ per ampere. This can result in a significant cost savings for circuits over 300 amperes.
What size 75 degree C conductors are required for a 600 ampere service that has a calculated demand load of 550 amperre?
What size conductors(2) would be required in one raceway (nipple) for a 600 ampere service? The calculated demand load is 550 ampere.
When equipment grounding conductors are installed with circuit conductors that are run in parallel, each raceway must have an equipment grounding conductor sized according to the overcurrent protection device protecting the circuit.(True/False)
What size equipment grounding conductor is required in each of two raceways for a 600 ampere feeder?(Table 250.122)
Overcurrent protection devices have two ratings, overcurrent and _________.
Ampere interrupting current(AIC)
Ampere interrupting current (AIC) is for short circuit faults. They are meant to protect a device from _______ while trying to clear a fault.
The minimum interruption rating is _____ ampere for circuit breakers and _____ ampere for fuses.
Continuous Load Protection: Overcurrent protections devices are sized at no less than ____ percent of the continuous load, plus _____ percent of the noncontinuous load.
The next higher overcurrent protection device is permitted if Conductors do not supply multioutlet branch circuits for cord and plug connected loads; the ampacity of a conductor does not correspond with the standard ampere rating of a standard fuse or circuit breaker; The next size up breaker or fuse does not exceed 800 ampere.(True/False)
What size conductor is required for a 104 ampere continuous load that is protected with a 150 ampere breaker?
If the overcurrent protection device is over 800 ampere, the circuit conductor ampacity must not be ____ than the rating of the overcurrent protection device.
Air Conditioning: An air conditioner nameplate indicates the minimum circuit ampacity of 43 ampere and maximum fuse size of 60 ampere. What is the minimum size branch circuit conductor and the maximum size overcurrent protection device?(422.13)
No. 8, 60 ampere
Water Heater: What size conductor and protection device is required for a 4500 VA, 240 Volt water heater(422.11(e)?
#10AWG, 30 Amps
Motor: What size branch circuit conductor and short-circuit protection is required for a 2 horsepower (12 ampere) motor rated 230 volts?(240-6(a), 430-52(b))
no. 14, 30 ampere
Ambient temperature Derating Factor: Conductor ampacity adjustment does not apply if the different ambient is 10 feet or less and does not exceed -___ percent of the total length of the conductor.(310-15(a)(2)exception
What is the ampacity of No. 12 THHN when installed in a walk in cooler that has an ambient temperature of 50 degrees F? (310.15(B)(2)(a)
What is the ampacity of No. 6 THHN when installed on a roof that has an ambient temperature of 60 degrees C?(310.15(B)(2)(a)
Conductor Size: What size conductor is required to supply a 40 ampere load? The conductors pass through a room where the ambient temperature s 100 degrees F. (310.15(B)(2)(a)
No. 8 THHN
To find the correction factor for situation where four or more current carrying conductors are bundled together, consult Table _____.
Conductor bundle ampacity adjustment does ot apply to conductors that are in a conduit that does not exceed _____ inches in length.
What is the ampacity of four current-carrying No. 10 THHN conductors installed in a raceway or cable?
A raceway contains four current-carrying conductors. What size conductor is required to supply a 40 ampere non-continuous load?
No. 8 THHN
If the ambient temperature is different than 86 degrees F (30 degrees C) AND there are more than three conductors in a conduit or cable, You must multiply by both the temperature correction factor and the bundle adjustment factor(True/False)
What is the ampacity of four current-carrying No. 8 THHN conductors installed in ambient temperature of 100 degrees F?
The grounded neutral of a balanced 3-wire delta circuit or balance 4 wire wye circuit (is)(is not) considered a current carrying conductor.
The grounded neutral of a balanced 3 wire wye circuit (is)(is not) considered a current carrying conductor.
What is the neutral current for a balanced 16 ampere 3 wire 208Y/120-volt branch circuit of a 4 wire 3 phase wye system that supplies fluorescent lighting?
Both grounded and ungrounded conductors of a two wire circuit (are) (are not) considered current carrying.
Equipment rated 100 ampere or less must have the conductor sized no smaller than the 60 degree column of Table 310-15(B)(16). Equipment rated at more than 100 ampere must have the conductors sized no smaller than for the 75 degree column of Table 310-15(B)(16)(True/False)
Conductor Insulation Property(310.104): THHN can be described as thermoplastic insulation with a nylon cover; having a maximum operating temperature of 90 degrees C(True/False)
Conductor Allowable Ampacity(240.4(D): The maximum overcurrent protection device for a No. 14 is 15 ampere, No. 12 is 20 ampere, and No. 10 is 30 ampere. This is a general rule, but it does not apply to motors or air-conditioners according to Section 240-3.
Conductor Sizing(110-6): Conductor sizes are expressed in Amercan Wire Gauge (AWG) from No. 40 through No. 4/0. Conductors larger than _____ are expressed in circular mils.
Conductor Sizing(310-106(a): The smallest size conductor permitted for branch circuits, feeders, and services for residential, commercial, and industrial locations is _____.
No. 14 copper or No. 12 aluminum
Terminal Rating(110-14(c)(1): Equipment terminals rated 100 amperes or less (circuit breakers, fuses, etc.) and pressure connector terminals for No. 14 through No. 1 conductors shall have the conductor sized according to _____ degree temperature rating as ed in Table 310.15(a)(16)
Terminal Rating(110-14(C)(1): What is the minimum size THHN conductor that is permitted to terminate on a 70 ampere circuit breaker or fuse? Be sure to comply with the requirements of Section 110-14(c)(1)
Terminal Rating(110-14(C)(1): What size THHN conductor is required for a 70 ampere branch circuit if the circuit breaker and equipment is ed for 75 degrees C terminals and the load does not exceed 65 ampere?
Terminal Rating(110-14(C)(1): Terminals for equipment rated over 100 ampere and pressure connector terminals for conductors larger than No. 1 shall have the conductor sized according to 75 degree C temperature rating as ed in Table 310-15(a)(16)(True/False)
Terminal Rating(110-14(C)(1): What size THHN conductor is required for an air-conditioning unit if the nameplate requires a conductor ampacity of 34 ampere? Terminals of all the equipment and circuit breakers are rated 75 degrees C.
Terminal Rating(110-14(C)(1): What is the minimum size THHN conductor required for a 150 ampere circuit breaker or fuse? Be sure to comply with the requirements of Section 110-14(C)(2).
Terminal Rating: In general, THHN (90 degrees C) conductor ampacities cannot be used when sizing conductors; but when more than three current-carrying conductors are bundled together, or if the ambient temperature is greater than 86 degrees F, the allowable conductor ampacity must be decreased. THHN offers the opportunity of having a greater ampacity for conductor derating purposes, thereby permitting the same conductor to be used without having to increase the conductor size.(True/False)
Terminal Rating(110-14(C)(1):What size conductor is required to supply a 190 ampere load in a dry location? Terminals are rated 75 degrees C.
Conductors in Parallel(310-10(H)(1) : Phase and grounded (Neutral) conductors sized No. 1 AWG and larger are permitted to be connected in parallel.
Conductors in Paralle(310-10(H)(2) l:To ensure that the currents are evenly distributed between the parallel conductors, each conductor within a parallel set must be installed in the same type of raceway(metallic or nonmetallic) and must be the same length, material, circular mils, insulation type, and must terminate in the same method.(True/False)
Conductors in Parallel: (310-10(H)(1) When an electric relay (coil) is energized, the initial current can be very high, causing significant voltage drop. The reduced voltage at the coil (because of voltage drop) can cause the coils contacts to chatter (open and close like a buzzer) or not close at all. Paralleling of control wiring conductors is often necessary and permitted by the NEC to reduce the effects of voltage drop for long control runs.(True/False)
Conductors in Parallel: (310-10(H)(5)(250-122(F) When equipment grounding conductors are installed in parallel, each raceway must have a full-size equipment grounding conductor sized according to the overcurrent protection device rating of that circuit.(True/False)
Conductors in Parallel(310-10(H)(5): All parallel equipment grounding conductors are required to be a minimum No. 1/0.(True/False)
Conductors in Parallel(310-10(H)(1)(Table 250-122): What size equipment grounding conductor is required in each raceway for an 800 ampere, 500 kcmil feeder parallel in two raceways?
Conductors in Parallel: If we have an 800 ampere service with a calculated demand load of 750 ampere, what size 75 degree C conductors would be required if parallel in two raceways?
Conductors in Parallel(310-10(H)(1)(Table 250-122): What are the conductors required for a 250 ampere feeder paralleled in two raceways?
(210-196) There is no mandatory rule in the NEC limiting the voltage drop on conductors, but the Code recommends that we consider its effect.(True/False)
(240) One of the purposes of conductor overcurrent protection is to protect the conductors against excessive or dangerous heat.(True/False)
(240)(240-60(c), 240-83(c) Overcurrent devices must be designed and rated to clear fault current and must have a short-circuit interrupting rating sufficient for the available fault levels. The minimum interruption rating for circuit breakers is _____ ampere and ____ ampere for fuses.
(240)(240-6(A)) Standard sized circuit breakers and fuses include 25, 90, and 350 ampere.(True/False)
(240) (210-20(A))The maximum continuous load permitted on an overcurrent protection device is limited to _____ of the device rating.
(240-4(b)) IF the ampacity of a conductor does not correspond with the standard ampere rating of a fuse or circuit breaker, the next size up protection device is permitted. This applies only if the conductors supply multioutlet receptacles for portable cord and plug-connected loads.(True/False)
(240-3)(310-15(A)(16)What size conductor (75 degrees C) is required for a 70 ampere breaker that supplies a 70 ampere load?
(310-10 and 310-15) The temperature rating of a conductor is the maximum operating temperature the conductor insulation can withstand (without serious damage) over a prolonged period of time. The conductor allowable ampacities, ambient temperature correction factors, and correction factors all provide guidance for adjusting the conductor's ampacities for the different conditions.(True/False)
(Table 310-15(a)(16)): The ampacities in Table 310-15(a)(16) apply ony when the ambient temperature is 40 C and there are no more than two current-carrying conductors bundled together. If the ambient temperature is not 40 C or there are more than two current-carrying conductors in a raceway, the allowable ampacities must be adjusted to reflect the ampacity under the condition of use.(True/False)
(Table 310-15(a)(16)):What is the ampacity of No. 8 THHN conductors when installed in a walk in cooler if the ambient temperature is 50F?
(Table 310-15(a)(16)): What size conductor is required to feed a 16 ampere load when the conductors are in an ambient temperature of 100F? The circuit is protected with a 20-ampere overcurrent protection device.
No. 12 THHN
(Table 310-15(b)(3a)): When four or more current-carrying conductors are bundled together for more than _____, the conductor allowable ampacity must be reduced according to the factors ed in Table 310-15(b)(3a).
(Table 310-15(b)(3a)): A raceway contains eight current-carrying conductors. What size conductor is required to feed a 21 ampere noncontinuous lighting load? The overcurrent protection device is rated 30 ampere.
No. 10 THHN
Ambient Temperature and Conductor Bundling Derating Factors: What is the ampacity of eight current-carrying No. 10 THHN conductors installed in ambient temperature of 100F?
Current Carrying Conductors(310-15(B)(5) : The neutral conductor of a balanced 3-wire delta circuit, or 4 wire wye circuit is considered a current-carrying conductor for the purpose of applying the derating factors in Table 310-15(b)(2a).
Current Carrying Conductors(310-15(B)(5): The neutral conductor of a balanced 4 wire wye circuit that is at least 50 percent loaded with nonlinear loads (electric discharge lighting, electronic ballast, dimmers, controls, computers, laboratory test equipment, medical test equipment, recording studio equipment, etc.) is not considered a current-carrying conductor for the purpose of applying bundle adjustment factors.(True/False)
Current Carrying Conductors(310-15(B)(5): The neutral conductor of a balanced 3-wire wye circuit is not considered a current-carrying conductor for the purpose of applying bundle adjustment factors.(True/False)
(310-15(B)(3)(a)(2)The ampacity of a conductor can be different along the length of the conductor. The higher calculated ampacity can be used if the length of the lower ampacity is no more than 10 feet or no more than 10 percent of the length of the circuit conductors.(True/False)
(110-14(C) Most terminals are rated 60C for equipment 100 ampere and less and 75C for equipment terminals rated over 100 ampere. Regardless of the conductor ampacity, conductors must be sized no smaller than the terminal temperature rating.(True/False)
(240) A continuous load of 27 ampere requires the circuit overcurrent protection device to be sized at _____ ampere.
(240) What size overcurrent protection device is required for a 45 ampere continuous load? The circuit is in a raceway with 14 current carrying conductors.
(240) A department store ( continuous load) feeder supplies a lighting load of 103 ampere. The minimum size overcurrent protection device permitted for this feeder is _____ ampere.
(310-15(A)(16) A No. 2 TW conductor is installed in a location where the ambient temperature is expected to be 102F. The temperature correction factor for conductor ampacity in this location is _____.
(310-15(A)(16) If the ambient temperature is 71 C, the minimum insulation that a conductor must have and still have the capacity to carry current is _____.
(315-15(B)(3a) The ampacity of six current-carrying No. 4/0 XHHW aluminum conductors installed in a ground floor slab (wet location) is _____.
The ampacity of 15 current carrying No. 10 RHW aluminum conductors in an ambient temperature of 75F would be _____.
A No. _____ THHN conductor is required for a 19.7 ampere load if the ambient temperature is 75F and there are nine current-carrying conductors in the raceway.
The ampacity of the nine current-carrying No. 10 THW conductors installed in a 20 inch long raceway is_____.
The ampacity of 10 current-carrying No. 6 THHW conductors installed in an 18 inch long raceway with an ambient temperature of 39C is ____.
A raceway contains the following: One 4-wire multiwire branch circuit that supplies a balanced incandescent 120 volt lighting load; one 4-wire multiwire branch circuit that supplies a balanced 120 volt fluorescent lighting load; two conductors that supply a receptacle; and there is one equipment grounding conductor. The system is 3-phase 208Y/120 volts. Taking all these factors into consideration, how many of these conductors are considered current carrying?
There is a total of nine No. 10 THW conductors in a raceway. The system voltage is 3-phase, 208Y/120 Volts. One conductor is an equipment grounding conductor; four conductors supply a 4 wire multiwire branch circuit for balanced electric-discharge lighting, and the remaining conductors supply a 4-wire multiwire branch circuit for balanced incandescent lighting. Taking all of these factors into consideration, how many of these conductors are considered current-carrying?
(250) A service that contains No. 12 service-entrance conductors, shall require a No. _____ grounding electrode conductor.
(250-68(B)) The connections (attachment) of the grounding electrode conductor to a grounding electrode shall be made in a manner that will ensure a permanent and effective _____.
(250-70) The connection of the grounding electrode conductor to a buried grounding electrode (driven ground rod) shall be made with a ed terminal device that is _____.
Suitable for direct burial
(250-86) Metal enclosures for conductors added to existing installations of nonmetallic sheathed cable, knob and tube wiring, or open wiring, which do not provide an equipment ground, are not required to be grounded if they are less than25 feet long free from probable contact with grounded conductive material.(True/False)
(250-94, bonding of other systems) An accessible point must be available for bonding of communications systems to the building grounding electrode. This Section requires the accessible bonding point to be exposed metallic service raceways, exposed grounding electrode conductor, or 6 inches of No. 6 copper conductor connected to the service equipment or raceway(True/False)
(250-96(a)) Metal parts that serve as the grounding conductor must be ______ together to ensure electrical continuity and have the capacity to conduct safely any fault current likely to be imposed.
(250-96(b)) Where required for the reduction of electric noise for electronic equipment, electrical continuity of metal raceway is not required, and the metal raceway can terminate to a(n) ______ nonmetallic fittings(s)or spacer on the electronic equipment.
(250-102(c)(1)) The bonding jumper for service raceways must be sized according to the _____.
Service entrance conductor size
(Table 250-122) What is the minimum size equipment grounding conductor required for equipment connected to a 40 ampere rated circuit?
(250-104(A)(1)) A building or structure, which is supplied by a feeder, must have the interior metal water piping system bonded with a conductor sized from _____.
(250-110) Exposed noncurrent-carrying metal parts likely to become energized must be grounded where within 8 feet vertically or 5 feet horizontally of ground or grounded objects, located in wet or damp locations, or in electrical contact with metal(True/False).
(250-114(3)) Which of the following appliances installed in residential occupancies need not be grounded?
(250-119) The equipment grounding conductor shall be identified by a continuous outer green finish, being bare, or a continuous outer green finish with one or more yellow stripes.(True/False)
(250-122(c)) Where a single equipment grounding conductor is used for multiple circuits in the same raceway, the single equipment grounding conductor must be sized according to _____.
the largest overcurrent device protecting conductors in the raceway
(250-122) Where necessary to comply with Section 250-2(d), the equipment grounding conductors shall be sized larger than specified in ______.
(250) When considering whether equipment is effectively grounded, the structural metal frame of a building shall be permitted to be used as the required equipment grounding conductor for AC equipment.(True/False)
(250-146) An _____ shall be used to connect the grounding terminal of a grounding - type receptacle to a grounded box.
Equipment bonding jumper
(250-146(A)) Equipment bonding jumper shall be used to connect the grounding terminal of a grounding-type receptacle to a grounded box. Where the box is surface mounted, direct metal to metal contact between the device yoke and the box shall be permitted to ground the receptacle to the box.(True/False)
(250-148) Where there are multiple equipment grounding conductors present in a receptacle outlet box, all equipment grounding conductors must be spliced and a pigtail brought out for the receptacle.
(250-164(A)) DC systems to be grounded and supplied from an off premises source shall have the grounding connection made at _____.
One of more supply stations
(250-172) Cases or frames of instrument transformers are not required to be grounded when accessible to qualified persons only or for current transformers where the primary is not over 150 volts to ground and which are used exclusively to supply current to meters.(True/False)
(280-12)The conductor used to connect the surge arrester to _____ shall not be any longer than necessary.
(300-2) Unless specified elsewhere in the Code, Chapter 3 shall be used for voltages of _____.
600 volts nominal, or less
(300-3(c)(1)) Circuit conductors that operate at 277 volts (with 600 volt insulation) may occupy the same enclosure or raceway with 48-volt dc conductors that have an insulation rating of 300 volts.(True/False)
(300-4(b)(1)) Where nonmetallic sheathed cables pass through cut or drilled slots or holes in metal members, the cable needs to be protected by bushings or grommets securely covering all metal edges fastened in the opening prior to installation of the cable.(True/False)
(Table 300-5) UF cable is used to supply power to a 120 volt 15 ampere GFCI protected circuit. If the cable is installed outdoors under the driveway of a one-family dwelling, the minimum cover requirement is _____ inches.
(300-5(D)(1)) Where underground conductors and cables emerge from underground, they shall be protected to a point ____ feet above finished grade. In no case shall the protection be required to exceed 18 inches below grade.
(300-5(F)) Backfill used for underground wiring must not damage the wiring method, contribute to the corrosion of the raceway or prevent compaction of the fill.(True/False)
(300-5(I)) All conductors of a circuit are required to be in the same raceway and in close proximity in the same trench.(True/False)
(300-6(D)) The provisions required for mounting conduits on indoor walls or in rooms that must be hosed down frequently is ______ between the mounting surface and the electrical equipment.
A ¼ inch air space
(300-10) All metal raceways, cable armor, boxes, fittings, cabinets and other enclosures for conductors must be _____ joined together to form a continuous electrical conductor.
(300-13(A)) Conductors in raceways must be _____ between outlet devices and there shall be no splice or tap within a raceway itself.
(300-14) An 8" x 8" x 4" deep junction/splice box would only require 6 inches of free conductor measured from the point in the box where the conductors enter the enclosure. The 3 inch outside the box rule _____ apply.
(300-16(B)) A bushing can be used instead of a box where conductors emerge from a raceway and enter or terminate at equipment such as switchboards, unenclosed control equipment, or similar equipment.(True/False)
(300-18(A)) The NEC permits prewired raceway assemblies where specifically permitted elsewhere in the Code.(True/False)
(300-19, Table 300-19(A)) A 100 foot vertical run of No. 4/0 copper requires the conductors to be supported at _____ locations.
(300-21) Electrical installations in hollow spaces, vertical shafts, and ventilation or air handling ducts shall be so made that the possible spread of fire or products of combustion will not be ______.
(300-22(B)) Wiring methods permitted in ducts or plenums used for environmental air include _______.
Electrical metallic tubing
(300-22C) The space above a dropped ceiling used for environmental air is considered as _____ and the wiring limitations of Section _____ apply.
Other spaces, 300-22(c)
(300-23) Wiring methods and equipment installed behind panels designed to permit access (such as drop ceilings) shall be so arranged and secured to permit the removal of panels to give access to electrical equipment.(True/False)
(590-3(D)) Temporary wiring must be _____ immediately upon the completion of the purpose for which it was installed.
(590-4(C)) Type NM and NMC cables can be used for temporary wiring in structures of a height of 6 feet, 12 feet, or 18 feet.(True/False)
(590-4(E)) Multiwire branch circuits for temporary wiring shall be provided with a means to disconnect simultaneously all _____ conductors at the power outlet or panelboard where the branch circuit originated.
(590-4(J)) Cable assemblies, as well as flexible cords and cables, shall be supported at intervals that ensure protection from physical damage. Support shall be in the form of staples, cable ties, straps or similar fittings designed as not to damage the cable or cord assembly.(True/False)
(590-6(A)(1)) All 125 volt single phase 15, 20 and 30 ampere receptacle outlets in use by personnel for temporary power shall have ground-fault circuit-interrupter protection for personnel.(True/False)
(310-10(H)(1)) In general, the minimum size phase, neutral or grounded conductor permitted for use in parallel is No. ___.
(Table 310-106(A)) The minimum size conductor permitted in a commercial building for branch circuits under 600 volts is No. _____.
(310-15(3)) Where conductors of different insulation are associated together, the limiting temperature of any conductor shall not be exceeded.(True/False)
(310-120(C)) Suffixes to designate the number of conductors within a cable are D "Two insulated conductors laid in parallel" or M "Two or more insulated conductors twisted spirally".(True/False)
(310) Where six current-carrying conductors are run in the same conduit or cable, the ampacity of each conductor shall be adjusted by a factor of _____ percent.
(310) On a 4 wire-3-phase wye circuit, where the major portion of the load consists of electrical discharge lighting, data processing equipment , or other harmonic current inducting loads, the neutral conductor shall be counted when applying Section 310-15(b)(2) adjustment factors.(True/False)
(310-15(B)(2)(A)) In designing circuits, the current-carrying capacity of conductors should be corrected for heat at room temperatures above ______ degrees F.
(310-60(A)) Thermal resistivety is the reciprocal of thermal conductivity; it is designated Rho and expressed in units of ______.
(310-60(C)(71)) Table 310-71 provides ampacities of an insulated three-conductor copper cable isolated in air, based on conductor temperature of 90 C (194 F) and ambient air temperature of 40 C (104 F) . If the conductor size is No. 4/0 AWG, MV-105, and the voltage range is 2001 to 5000, the ampacity is _____ amperes
(392-12) Cable tray systems shall not be used in hoistways or _______.
Where subject to physical damage.
(Table 392-60(A) (b)) Steel cable trays shall not be used as equipment grounding conductors for circuits with ground-fault protection above _____ amperes.
(3392-56) Cable ______ made and insulated by approved methods shall be permitted to be located within a cable tray provided they are accessible They may project above the side rails where not subject to physical damage.
(392-20(C)) Where single conductor cables comprising each phase or neutral of a circuit are connected in parallel in a cable tray, the conductors shall be installed _____ to prevent current unbalance in the paralleled conductors due to inductive reactance.
In groups consisting of not more than one conductor per phase or neutral
(398-2) Open wiring on insulators is a(n) _____ wiring method using cleats, knobs, tubes, and flexible tubing for the protection and support of single insulated conductors run in or on buildings, and not concealed by the building structure.
(398-30(D)) Where screws are used to mount knobs for the support of open wiring on insulators, they shall be of a length sufficient to penetrate the wood to a depth equal to at least _____ the height of the knob and the full thickness of the cleat.
(398-19) Open conductors shall be separated at least ______ inches from metal raceways, piping, or other conducting material, and from any exposed lighting, power, or signaling conductor, or shall be separated by a continuous and firmly fixed nonconductor in addition to the nsulation of the conductor.
(398-15(C)) Where open conductors cross ceiling joists and wall studs and are exposed to physical damage, they shall be protected by a substantial running board. Running boards shall extend at least _____ inch outside the conductors, but not more than ______ inches, and the protecting sides shall be at least 2 inches high and at least 1 inch nominal in thickness.
(396-30) The messenger shall be supported at dead ends and at intermediate locations so as to eliminate _____ on the conductors.
(394-12) Concealed knob and tube wiring shall be permitted to be used in commercial garages, theaters and similar locations, motion picture studios, hazardous (classified) locations, or in the hollow spaces of walls, ceilings, and attics where such spaces are insulated by loose, rolled or foamed in place insulating material that envelops the conductors(True/False).
(394-17) Where knob and tube conductors pass through wood cross members in plastered partitions, conductors shall be protected by noncombustible, nonabsorbent, insulating tubes extending not less then _____ inches beyong the wood member.
(326-2) Type IGS cable is a factory assembly of one or more conductors, each individually insulated and enclosed in a loose fit nonmetallic flexible conduit as an integrated gas spacer cable rated _____ volts.
(324-10(B)(2)) General use branch circuits using flat conductor cable shall not exceed_____ amperes.
(324-42(A)) Receptacles, receptacle housings, and self-contained devices used with flat conductor cable systems shall be _____.
Identified for this use
(324-56(B)) Each FCC transition assembly shall incorporate means for facilitating the entry of the type FCC cable into the assembly; connecting the Type FCC cable to grounded conductors; and electrically connecting the assembly to the metal cable shields and grounding conductors.(True/False)
(332-24(2)) The radius of the inner edge of any bend shall not be less than ____ times the MI cable diameter for a cable that has a diameter of over ¾ inch.
(332-40(B)) Where MI cable terminates, a _____ shall be provided immediately after stripping to prevent the entrance of moisture into the insulation.
(332-112) The conductor insulation in Type MI cable shall be a highly compressed refractory mineral that will provide proper _____ for the conductors.
(362-2) Electrical nonmetallic tubing is composed of a material that is resistant to moisture, chemical atmospheres, and is ______.
(362-10(6) Electrical nonmetallic tubing and fittings shall be permitted to be _____ in a concrete slab on grade where the tubing is placed upon sand or approved screenings.
Encased and embedded
(362-28) All cut ends of electrical nonmetallic tubing shall be trimmed inside and ____ to remove rough edges.
(362-46) Bushings or adapters are required at electrical nonmetallic tubing terminations to protect the conductors from abrasion.(True/False)
(320-30(B)) AC cable shall be supported at intervals not exceeding 4 ½ feet and the cable shall be secured within _____ inches of cable termination.
(320-15) Although exposed Type AC cable is required to closely follow the surface of the building, it can be used on the underside of floor joists in basements where supported at each joist where not subject to damage.(True/False)
(320-15) Where armor cable is run on the side of rafters, studs, or floor joists in an accessible attic, protection is required for the cable with running boards.(True/False)
(334-10) Type NM, Type NMC cables shall be permitted to be used in one and two family dwellings.(True/False)
(334-15(C)) Where NMC cable is run at angles with joists in unfinished basements it shall be permissible to secure cables not smaller than ____ conductors directory to the lower edge of the joist.
(334-17) Nonmetallic sheathed cables run through framing members are considered to be adequately supported.(True/False)
(334-80) The ampacity of nonmetallic sheath cable shall be hat of 60 C as ed in Table 310-15(A)(16). However the 90 C ampacity ed in Table 310-15(A)(16) can be used for ampacity adjustment purposes, provided the final adjusted ampacity does not exceed that of a _____ rated conductor.
(338-2) _____ is a type of multiconductor cable permitted for use as an underground service entrance cable.
(338-10(B)(4)(b)) requirements of Article 334-30 the cable shall be secured within ____ inches of termination and 4 ½ feet, and when installed underground the cable shall comply with the underground requirements in Article 339 - Underground Feeder Cable.
(340-10) Type UF cable is permitted for interior use, wet locations, or for direct burial.(True/False)
(340-12) Type UF cable shall not be used where subject to physical damage. When this cable is subject to physical damage, it shall be protected by a suitable method such as a raceway.(True/False)
(382-2) The classification of nonmetallic extensions includes surface extensions intended for mounting directly to the surface of walls and surface extensions intended for mounting directly on the surface of ceilings. (True/False)
(382-56) Receptacle type tap connectors for nonmetallic extensions shall be of the _____.
(382-30(A)) Nonmetallic extensions shall be secured in place by approved means at intervals not exceeding _____ inches.
(354-10) The use of nonmetallic conduit with conductors shall be permitted for direct burial underground installation; in cinder fill; or encased or embedded in concrete.(True/False)
(354-28) For ______, nonmetallic underground conduit with conductors shall be trimmed away from the conductors or cables using an approved method that will not damage the conductor or cable insulation or jacket.
(342-10(D)) Materials such as straps, bolts, screws, etc., associated with the installation of intermediate metal conduit in concrete, in direct contact with the earth are required to be ______.
(342-42(A)) Threadless couplings approved for use with intermediate etal conduit in wet locations shall be of the _____ type.
(342-30(A)) Intermediate metal conduit shall be firmly fastened within _____ of each outlet box, junction box, device box, fitting, cabinet, or other conduit termination.
(342-30(B)) When IMC is installed through bored or punched holes in framing members, additional support requirements are not necessary. This applies to both wood and metal framing members.(True/False)
(344-10(B)(1)) Rigid metal conduit shall be permitted to be installed in concrete, in direct contact with the earth, or in areas subject to severe corrosive influences where protected by ____ and judged suitable for the condition.
(344-42(A)) Where threadless couplings and connectors used with rigid metal conduit are buried in masonry or concrete, they shall be of the_____ type.
(343-351) The minimum radius for a bend of 1 inch rigid conduit with three No. 10 TW conductors is ____ inches, if a one shot bender is used.
(Table 344-30(B)(2) ) Straight runs of 1 inch rigid metal conduit using threaded couplings may be secured at intervals not exceeding _____ feet.
(352-100) Rigid nonmetallic conduit and fittings used above ground shall be resistant to moisture and chemical atmospheres, low temperatures and sunlight and distortion from heat.(True/False)
(352-60) An equipment grounding conductor is not required in the conduit if the grounded (neutral) conductor is used to ground equipment as permitted in Section 250-142.(True/False)
(358-2(A)(B)) The minimum and maximum size of EMT is _____ inches, except for special installations.
½ to 4
(358-26) A run of electrical metallic tubing between outlet boxes shall not exceed _____ close to the box.
360 degrees total
(348) The maximum run length of 3/8 inch flexible metal conduit for any circuit is_____ feet.
(348-30(A)(Exp 3) 3/8 inch flexible metal conduit used for the supply to recessed lighting fixtures must have the raceway secured every _____ feet.
(350-10) The use of ed and marked liquidtight flexible metal conduit shall be permitted for direct burial where ed and marked for the purpose, exposed work, and concealed work.(True/False)
(350-30(A)) Liquidtight flexible conduit where used as a fixed raceway, must be secured within _____ inches(es) on each side of the box and at intervals not exceeding _____ feet.
12, 4 ½
(350-60) Where liquidtight flexible conduit is used to connect to equipment and flexibility where required, a separate _____ conductor must be installed.
Equipment grounding conductor
(368-12(2)) In general, the voltage limitation between conductors in a surface metal raceway shall not exceed _____ volts unless the metal has a thickness ed for higher voltage.
(368-10) It is permissible to run unbroken lengths of surface metal raceways through dry walls, partitions, or floors.(True/False)
(368-100)Surface metal raceways and their fittings shall be so designed that the sections can be electrically or mechanically coupled together and installed without subjecting wires to abrasion.(True/False)
(390-4(b))Underfloor raceways spaced less than 1 inch apart shall be covered with concrete to a depth of _____ inches.
(390-8) When an outlet from an underfloor raceway is discontinued, the circuit conductors supplying the outlet _____.
Shall be removed from the raceway
(374-9)A junction box used with a cellular metal floor raceway shall be level with the floor grade, sealed against the entrance of water or concrete, and metal and electrically continuous.(True/False)
(372-2)In cellular concrete floor raceways, a "cell" shall be defined as a single, enclosed _____ space in a floor made of precast cellular concrete slabs, the direction of the cell being parallel to the direction of the floor member.
(372-6)Connections from cellular concrete floor raceway headers to cabinets shall be made by means of ed metal raceways or PVC raceways.(True/False)
(372-13) When an outlet is discontinued, abandoned or removed from a cellular concrete floor raceway, the sections of circuit conductors supplying the outlet shall be removed from the raceway.(True/False)
(378-21) Conductors larger than that for which the wireway is designed shall be permitted to be installed in any wireway.(True/False)
(376-30) Wireways where run horizontally shall be supported at each end and the distance between supports shall not exceed _____ feet.
(332-10(1)) Flat cable assemblies shall be permitted only as branch circuits to supply suitable tap devices for lighting, small power, or small appliance loads.(True/False)
(332-40(D)) All extensions from flat cable assemblies shall be made by approved wiring methods, within the _____, installed at either end of the flat cable assembly runs.
(368-30) Busways shall be securely supported, unless otherwise designed, and marked at intervals not to exceed _____ feet.
(368-17(C)) Where devices or plug-in connections for tapping off feeder or branch circuits fro busways consist of an externally operable fusible switch, ropes, chains, or sticks shall be provided for operation of the disconnecting means from the floor.(True/False)
(370-3) Cablebus framework, where _____, shall be permitted as the equipment grounding conductor for branch circuits and feeders.