IEC Year 2 Chapters 214 & 215
Where a cable or raceway-type wiring method is installed through bored holes in joists, rafters, or wood members, holes shall be bored so that the edge of the hole is not less than ___ from the nearest edge of the wood member.
1 1/4" 310.16
A 175-Amp breaker protects a feeder that originates in a 120/240-volt, 1-ph, 3-wire service panel in a residence. Which of the following conductors is the smallest size permitted for the feeder?
1/0, T310.16
Where cables assemblies with nonmetallic sheathes are used, the sheath shall extend not less than ___ inside the box and beyond any cable clamp.
1/4
What is the ampacity of a 1/0 TW copper conductor?
125 amps
According to the NEC®, the smallest size permitted for branch circuit conductors suitable for supplying other than cooking appliances is ___ AWG
14
The minimum size conductor permitted in commercial buildings for branch circuits up to and including 2000 volts is ___ AWG.
14
How much current can each conductor carry? Six, current-carrying 250 kcmil conductors are run in a pipe that is located in a 129°F ambient temperature location? The 75°C OCPD terminations are far away from the high temp area.
176
In completed installations, each outlet box shall have a ___.
Cover
4 AWG conductors can be spliced inside an LB type conduit body using ___.
Crimp Connectors, Screw Type splice connectors, Wire Nuts 300.13 (A)
Where conductors carrying alternating current are installed in metal enclosures or metal raceways, they shall be arranged so as to avoid heating the surrounding metal by ___.
Induction 300.20
Conductor sizes are given in ___or ___.
AWG, Circular Mills
When balancing a 3-wire circuit, from a single-phase 230/115-volt system, the neutral conductor ___.
should carry the unbalanced current in each ungrounded conductor 310.15 (E) (1)
All metal raceways, cable armor, fittings, cabinets, and other metal enclosures for conductors must be ___ joined together to form a continuous electrical conductor.
metallically, 300.10
A cabinet or cutout box is constructed of sheet steel, the metal thickness shall not be less than ___ inch uncoated.
.053, 312.100(B)
XHHW 500 kcmil conductors have an insulation that is ___ mm thick.
1.65, 310.4 (A)
The minimum size THWN/THHN aluminum conductor permitted to serve a 95 amp load that will operate continuously is ___ AWG.
1/0
What is the smallest conductor permitted to be connected in parallel
1/0 AWG, 310.10 (G) (1)
Which of the following THHN/THWN copper conductors is the smallest size permitted for a feeder where a 150 A breaker protects the feeder? The feeder originates in the 120/240-volt, 1-ph, 3-wire service panel in a bakery.
1/0, T310.16
The Code permits a ___" maximum space between the panel enclosure ("can") and the panel cover
1/4, 312.3
Non combustible surfaces that are broken or incomplete shall be repaired so there will be no gaps or open spaces greater than ___ inch at the edge of the fitting or box.
1/8
What is the circular mil area of a 3/0 AWG conductor?
167,800, Chapter 9 T8
No additional support is required for this installation (the earth can support the conduits) if the conduit length from the finish surface (dirt here) to the box is ___ inches or less.
18
For a raceway containing 30 current carrying conductors, the ampacity of each conductor shall be reduced to ___ percent of that for a single conductor.
45, 310.15 (C) (1)
A nipple contains four 6 AWG THW copper current-carrying conductors. The ampacity of each conductor would be ___ amperes.
65, Don't need to derate because it's a nipple
When eight (8) current-carrying conductors are in one conduit, the ampacity of each conductor is adjusted to ___ percent.
70, 310.15 (C) (1)
Conductors in raceways must be ___ between outlet devices, and there shall be no splices or taps within the raceways.
Continuous, 300.15 (A)
Fittings and connectors shall be used only with the specific wiring methods for which they are ___.
Designed and Listed
Where multiwire branch circuits are connected to breakers in a 277/480-volt, 3Ø, 4-wire panel, the neutral has to be counted as a current-carrying conductor (when applying ampacity correction factors) where the connected loads consist of ___ lighting.
HID and Fluorescent 310.15 (E) (3)
Which of the following about the equipment grounding conductor is true? I. It does not count as a current-carrying conductor. II. A bare, covered or insulated conductor shall be permitted. III. For conduit fill, each grounding conductor counts as one conductor.
I, II, and III 310.15 (F)
Which of conductor insulation is oil resistant?
MTW
The ___ rating of a conductor is the maximum temperature, at any location along its length, that the conductor can withstand over a prolonged period of time without serious degradation.
Temperature
An electrician needs to install a surface mounted, nonmetallic, weatherproof cabinet on the outside of a concrete block building. Since the cabinet must be mounted in a wet location, it must be mounted so there is at least ___ inch(es) of airspace between the cabinet and the wall.
0, 312.2
A cable, raceway, or box, installed in exposed or concealed locations under metal-corrugated sheet roof decking, shall be installed and supported so there is not less than ___ measured from the lowest surface of the roof decking to the top of the cable, raceway, or box.
1 1/2" 300 (4) (E)
Outlet boxes that do not enclose devices or utilization equipment shall have a minimum internal depth of ___ inch(es).
1/2
In areas where the walls are frequently washed, conduit should be mounted with a ___ inch air space between the wall and the conduit.
1/4, 300.6 (1)
A metal switch enclosure installed in a damp or wet location shall be spaced at least ___" off the mounting surface.
1/4, 312.2
Determine the maximum current-carrying capacity for each conductor when four 1/0 AWG THW current-carrying copper conductors are installed in a common raceway with an ambient temperature of 86 degrees F.
120 amps
Inside a 277/480-volt, 3-ph, 4-wire panelboard, a 1/0 conductor that is connected to a circuit breaker can carry ___ amps of current.
150, The answer is the same if it was a 120 volt circuit
Underground service conductors that are not encased in concrete and that are buried ___ or more below grade shall have their location identified by a warning ribbon that is placed at least 12 inches above the underground installation.
18", 305.5
The maximum temperature rating of a THHN conductor is ___°F in a dry location.
194, 310.4 (A)
For a 200-A residential service, the smallest service conductors permitted by the NEC® are ___ AWG THHN/THWN.
2/0
Boxes are to be mounted in non-combustible walls so that the box is flush with the finished wall surface. However, the NEC® permits these boxes to be set back ___ from the finished wall surface.
3/16 or 1/8
The minimum thickness for a cast aluminum box measuring 6" × 4" × 31/2" is ___ inches.
3/32
Cabinets and cutout boxes shall be deep enough to allow the closing of the doors when ___-ampere branch-circuit panelboard switches are in any position, when combination cutout switches are in any position, or when other single-throw switches are opened as far as their construction permits.
30, 312.101(B)
A feeder needs to be installed to supply power to a load that will draw 800 amps. The circuit breaker will be rated at 800 amps. There will be 3 parallel conduits run for the feeder. You will need to install at least ___ AWG or kcmil conductors in each conduit.
300
A 21/2" rigid metal conduit enters the back of a pull box that has a removable cover on the opposite side. The raceway encloses four 4/0 AWG THHN copper conductors and one 4 AWG equipment grounding conductor. The minimum depth (distance from the entry wall to the cover) for this pull box is ___ inch(es).
4, 314.28 (2) exp, go to 312.6(A)
Luminaires weighing more than ___ pounds are required to be supported independently of the outlet box.
50
When installed in raceways, conductors ___ AWG and larger shall be stranded.
8, 310.3 (C)
A ceiling fan that weighs ___ pounds or less can be supported by an outlet box that is identified for such use and has "maximum weight to be supported — 70 lbs" stamped into the box.
70
What is the insulation temperature rating of type THWN wire in a wet location?
75 C
When a single-gang nonmetallic outlet box does not have a clamp or connector, the maximum distance permitted between the box and the first strap in a NM cable installation is ___ inches.
8
If the equipment terminals are listed for 75°C, what size THHN conductors are required for a 50 ampere circuit?
8 AWG, 310.16
The minimum wire bending space required at the top and bottom of a panelboard that has three 3/0 AWG conductors connected to each busbar is ___.
8", 312.6(B)(2)
The ampacity of conductors is derated when the ambient temperature exceeds ___ºF.
86, T310.16
Type THW insulation has a ___ degree C rating for use in wiring through fixtures.
90
According to ___ in the NEC®, unused knockouts and other openings in electrical boxes and cabinets are required to be closed: 312.5(A) 110.12(A) 314.17(A)
All of these
Cabinets and cutout boxes shall have ___ to accommodate all conductors installed in them without crowding.
Approved space, 312.7
Insulated conductors used in wet locations shall ___.
Be moisture-impervious metal sheathed, have an insulation type with a "W" suffix, be listed for wet locations
In vertical conduit runs, such as up through a high-rise building, conductors made of aluminum have support requirements that are ___ than for copper conductors.
Closer together 300.19 (A)
Dual-rated THHN/THWN conductors have an insulation that permits installation in ___ locations.
Dry, damp, wet 310.4 (A)
Wiring methods permitted in ducts or plenums specifically fabricated to transport environmental air include ___.
Electrical metallic tubing
To avoid heating problems due to induction, the Code generally prohibits installing a single conductor of an alternating-current (ac) system in a metallic raceway. Which of the following single conductors of an ac system is permitted to be installed by itself in a metallic raceway?
Grounding electrode conductor 300.20 (A) exp
Suffixes that designate the number of conductors within a cable include ___. I. D - two insulated conductors laid parallel II. M - two or more insulated conductors twisted spirally III. T - two or more insulated conductors twisted in parallel
I and II only, 310.8 (C)
The parallel conductors in each phase or neutral shall ___. I. have the same insulation type and conductor material II. be the same size in cma III. be the same length and be terminated in the same manner
I, II, and III 310.10 (G) (2)
In walls or ceilings constructed of ___, it is acceptable to have the front edge of the box set back as much as 1/4 inch from the finish surface.
Sheetrock
Conductors with thermoplastic and fibrous outer braid Type TBS insulation are used for wiring ___.
Switchboards Only
Which of the following are permitted to be buried in a trench underground? The wiring will be covered with stabilized sand to prevent physical damage.
Type MI Cable
Insulated conductors and cables installed in wet locations must have a ___ designation in their type marking.
W
Which of the following conductors can be used in a damp location?
XHH 310.4 (1)
In a 480/277-volt, 3Ø, 4-W panel, a wire connected to breaker 41 is permitted by the NEC® to be ___ in color. A 42-circuit panelboard is shown above. (Question 7 on 214.2)
Yellow, Blue, Orange
When making up the branch circuit wires to the breakers in a newly installed panelboard, you found that some of the wires were cut too short. Does the NEC® permit any of these to be spliced with wire nuts so that another piece of wire can be added to be able to reach the breaker or the neutral bar?
Yes, 312.8 (A)
Under certain conditions, the uninsulated conductor in nonmetallic-sheathed cable ___ permitted to be used as a current-carrying conductor ("hot" or neutral). Note: NM cable is not permitted to be used as service-entrance cable.
is not
When several AC, MC, or NMC cables are installed next to each other in a bundle, the conductors in the cables are able to carry ___ current than if the cables were separated.
less
Nonmetallic boxes shall be suitable for the lowest ___ conductor entering the box.
temperature-rated
